Knives Out

Knives Out is a 2019 American mystery film written and directed by Rian Johnson. Daniel Craig leads an eleven-actor ensemble cast as Benoit Blanc, famed private detective summoned to investigate the death of bestselling author Harlan Thrombey (Christopher Plummer). Although police rule Harlan's case a suicide, Blanc suspects foul play and examines a host of clues and deceptive red herrings to ascertain his true manner of death. Johnson produced Knives Out with longtime collaborator Ram Bergman. Lionsgate managed the film's commercial distribution, and funding was sourced through MRC and a multimillion-dollar tax subsidy from the Massachusetts state government.

Johnson conceived Knives Out in the mid-2000s. Seeking to modernize the whodunit films of the mid-twentieth century, the director was inspired by his interest in big-screen movie adaptations of Agatha Christie's stories. Johnson then shifted his attention to creation of his 2017 film Star Wars: The Last Jedi, halting further progress on Knives Out. Development resumed the following year when Johnson wrote the screenplay in six or seven months. He devised a framework of tonal shifts to escalate tension between the characters, and informed elements of the story with his experience coping with intense culture war backlash to The Last Jedi. Principal photography began in October 2018 on a $40 million budget and wrapped that December. Shooting took place on location in suburban Boston. Nathan Johnson composed the film's classical score, which drew on an eclectic array of his and Rian's favorite symphonic movie scores. Knives Out has been read as work that investigates class warfare, wealth inequality, immigration, and race in contemporary American society.

Knives Out premiered at the 44th Toronto International Film Festival on September 7, 2019, and was distributed to American theaters on November 27 to major critical and commercial success. It was chosen as one of the year's top films by the National Board of Review and the American Film Institute, and finished the theatrical run grossing $312.9 million at the global box office. Critics distinguished the film's plot and actors for praise, though some aspects of the writing and performance drew criticism. It was nominated for multiple awards, among them three Golden Globes, a British Academy Film Award (BAFTA), and an Academy Award for Best Original Screenplay. Knives Out is the first entry of what became a franchise that includes two more films—Glass Onion: A Knives Out Mystery (2022) and Wake Up Dead Man: A Knives Out Mystery (2025).

Plot
The family of Harlan Thrombey, a wealthy mystery novelist, attends his 85th birthday party at his Massachusetts mansion. The next morning, Harlan's housekeeper, Fran, discovers him dead with a slit throat. Police detectives Lieutenant Elliot and Trooper Wagner believe Harlan committed suicide, but private detective Benoit Blanc is anonymously hired to investigate. Blanc learns that Harlan had strained relationships with his family members, giving several of them possible motives for murder.

Unknown to Blanc, Harlan's nurse, Marta Cabrera, believes she injected Harlan with a lethal dose of morphine after mixing up his medications the night after the party. Harlan instructed her to create a false alibi and then slit his own throat. Marta cannot lie without vomiting, so she gives accurate but incomplete answers when questioned. She agrees to assist Blanc's investigation and conceals evidence incriminating her. At the reading of Harlan's will, Marta is bequeathed his entire fortune; the Thrombeys are shocked by this. Harlan's grandson Ransom helps Marta escape the family, but coerces her into confessing to him. He offers help in exchange for a portion of Marta's inheritance. Meanwhile, the other Thrombeys try to persuade or threaten Marta into renouncing the inheritance, to no avail.

Marta receives a blackmail note containing a partial photocopy of Harlan's toxicology report. She and Ransom drive to the medical examiner's office to find it burned down. Marta receives an email proposing a rendezvous with the blackmailer. Blanc and the police spot them, and after a brief car chase, Ransom is arrested. At the rendezvous, Marta finds Fran drugged. She performs CPR and calls an ambulance. She confesses to Blanc but discovers that she has already been implicated by Ransom. Out of moral obligation, Marta believes she must confess to the Thrombeys, which would invalidate the bequest under the slayer rule.

Back at the mansion, Marta finds Fran's copy of the full toxicology report, which shows Harlan had only trace amounts of morphine in his blood. Blanc reveals his deductions to the police, Marta, and Ransom: that Harlan had told Ransom about his will, and that Ransom had then swapped Harlan's medicines to ensure that Marta would accidentally kill him and thus be ineligible to claim the inheritance. However, Marta actually gave Harlan the correct medication, recognizing it without reading the label due to her experience as a nurse; she only believed she had poisoned Harlan after reading the label. When the death was reported as a suicide, Ransom anonymously hired Blanc to expose Marta. Fran saw Ransom tampering with the crime scene and sent him the blackmail note. After Ransom realized Marta was not responsible for Harlan's death, but Marta still thought she was, he forwarded the blackmail letter to Marta and burned down the medical examiner's office to destroy evidence of her innocence. He then overdosed Fran with morphine, intending for Marta to get caught with Fran's corpse.

The hospital calls; Marta relays that Fran survived and will implicate Ransom. He scoffs that since his attempt to kill Fran failed, his lawyers will help him escape arson and attempted murder charges. Marta then vomits on him, revealing that she lied: Fran is dead. Realizing he has confessed to the murder, and that the police officers recorded his confession, Ransom attacks Marta with a knife from Harlan's collection, which turns out to be a retractable stage knife. The police promptly arrest him.

Blanc tells Marta he suspected early on that she played a part in Harlan's death, noting a drop of blood on her shoe. He tells her that her innocence prevailed because she made ethical choices all along that obstructed Ransom's attempts to incriminate her. As Ransom is taken into custody, Marta watches from the balcony of what is now her mansion, with the Thrombeys gathered outside.

Development


Director Rian Johnson first conceived of Knives Out after the completion of his first feature film, the low budget thriller Brick (2005). Johnson was eager to create a contemporary whodunit mystery influenced from film adaptations of books by detective fiction writer Agatha Christie, which he enjoyed as a child. His earliest vision of Knives Out was shaped by Alfred Hitchcock's advice regarding plot development, which argued that conventional whodunits too often relied on formulaic suspense, especially a climactic twist, to culminate the story. Once he had determined the story's goal, Johnson began conceiving ideas for the plot structure, the main one a framework of tonal shifts devised as a means of inciting tension in the story. The greatest challenge for the director was modernizing a genre studios deemed too antiquated for release.

Johnson hoped to commit to Knives Out after the release of his science fiction thriller Looper (2012), but suspended the project once Lucasfilm hired him to direct Star Wars: The Last Jedi (2017). He embedded elements of the Knives Out story with his experience coping with the intense culture war backlash to his Star Wars work. Johnson began the scriptwriting by January 2018, immediately after finishing his press tour for The Last Jedi, in a process lasting six or seven months. When the director showed a finished draft to friends, he recalled the response was cynical because his motivations were not well understood. Johnson took the film's name from a Radiohead song, saying it was a good title for a murder mystery.

Media coverage of Knives Out give conflicting accounts about the film's funding. One report circulated by Deadline claimed that MRC secured the script in an auction hosted by Creative Artists Agency and FilmNation to various investors at the 43rd Toronto International Film Festival. This account has been disputed by longtime collaborator Ram Bergman, who maintains there was never an auction, but that MRC was always the intended financier because of their sustained success with mass market films by auteurs—directors that wield significant autonomy over the artistic vision of their projects. Nevertheless, MRC financed the film's $40 million budget, plus generous backend compensation for Bergman, Johnson, and Daniel Craig, per the condition of their agreement. For Knives Out commercial distribution, MRC partnered with Lionsgate after Lionsgate, seeking to rebound from a year of mediocre box office showings, purchased a partial share of the distribution rights.

Casting


Employing an ensemble cast of established stars was one of Johnson's initial demands. He also drew upon the Agatha Christie movies, and chiefly Peter Ustinov-starred projects à la Death on the Nile (1978) and Evil Under the Sun (1982), for his casting choices because he felt they possessed a sense of spectacle worth replicating. The filmmakers focused on actors available in the six week interim before shooting for Knives Out began. Actors were chosen based on their ability to stand out in bit speaking parts and master an exaggerated, but not caricatured, comic performance. According to Johnson, the film's rapid progress readily facilitated his desired casting ambitions. Most of the Knives Out ensemble were signed in October and November 2018. Johnson named each of the characters after musicians he enjoyed because it was a simple practice to remember—for example, Joni Mitchell, Richard Thompson, and Steely Dan's Donald Fagen.

Daniel Craig came to Johnson's attention for his stage work and non-James Bond film roles. Johnson regarded him as a versatile actor yearning to challenge his abilities in a playful comedy role. Craig declined due to his contractual obligations to the then-forthcoming No Time to Die (2021), which was preparing to shoot around the same time, but logistical and creative disputes postponed the film's production by three months, giving the actor enough time to accept the offer. Once he read his mailed copy of the script, Craig agreed to join as the writing's tone and humor captivated him. The treatment of Blanc was not a fruitful task for Johnson initially; his first conception had been a Hercule Poirot clone "that was just a bunch of crazy quirks". To distinguish the character, the director outlined Blanc as a slightly pompous man with a flamboyant Southern accent, turning to Craig's ongoing feedback for more unique characterization. Craig undertook speech training with a dialect coach for two to three hours per day, studying playwright Tennessee Williams and author Shelby Foote, via interview footage from C-SPAN and the Ken Burns-helmed docuseries The Civil War (1990), to model Blanc's voice.

Casting director Mary Vernieu was responsible for hiring a suitable actress to portray Marta. She and the filmmakers did not favor one particular person for the part, unlike the other Knives Out characters, and scouted based on Johnson's preference for a relatively unknown actress exhibiting an underdog quality. They considered several candidates, including Ana de Armas, whose work piqued Vernieu's interest enough to be suggested in the casting discussions. Johnson was not familiar with de Armas' repertoire save for her starring role in Blade Runner 2049 (2017). He liked her acting, but believed she appeared too sensual to convincingly portray Marta. When Johnson met the actress for her audition, he noticed her ability to emote: "She's got that Audrey Hepburn-type thing, where her eyes just bring you in, and you're instantly on her side, and that's what we needed for the character." De Armas nearly passed the role because she found Marta's original character description clichéd. However, she was persuaded after reading the complete script, which emphasized resilience as a fundamental attribute of Marta. Another aspect that resonated with de Armas was Marta's immigrant backstory.

For the self-indulgent Ransom, Johnson envisioned Chris Evans after seeing him in the 2018 Broadway revival of Kenneth Lonergan's Lobby Hero, having been impressed with his performance as a contemptible villain. Evans was known mainly for his live-action role as Captain America in the Marvel Cinematic Universe, and Johnson aimed to exploit the actor's everyman persona to ignite tension between moviegoers and Ransom, saying, "You've got to see it not as baggage, but as ammunition. If there was someone in that part who the audience inherently wanted to like, that would help the arc overall." Although Evans was preparing to take a hiatus after finishing his duties for Avengers: Endgame (2019), he reconsidered when the producers relayed they would film near his home in Massachusetts.

Toni Collette said, for playing Joni, her biggest purpose was to find the humor in her character. Christopher Plummer, in one of his final film appearances before his death in 2021, described Harlan as a "stern, bright and rough-hewn" father with a crass sense of humor. Michael Shannon did not audition for the role of Walt and was contracted following an arranged lunch with Johnson in Brooklyn. For the part of Linda, Jamie Lee Curtis sympathized with her backstory as a woman fiercely scrutinized for her privilege. She stated, "I've been an actress for a long time, and I am also the daughter of someone famous, and people have a funny way of taking away anything you do creatively and reduce it to your privilege. Linda is very defensive about the assumption that she was given anything, and I've had the same defense." To prepare for her performance, Curtis immersed in activities she thought befitted her character's position as a matriarch, such as cooking meals.

Filming


Bergman was already assembling the filmmaking crew while Johnson made revisions to the script in early 2018. Johnson's instruction for the filmmakers was to find an estate that exuded Harlan's mystery writing sensibilities, citing the thriller Sleuth (1972) as a reference for recognizable visual elements. Bergman toured several homes with his scouting team before centering the film's production on a pair of sprawling mansions in suburban Boston: a privately owned nineteenth-century Gothic Revival manor for exterior shots, and the Ames Mansion, a 20-room historic landmark anchoring the Borderland State Park in Easton.

Most of the interior shots took place in the Ames Mansion, from intense confrontational scenes with Harlan and his relatives to conversational scenes of Blanc's investigation. A problem that challenged the production was the logistics of the mansions, for neither had the sufficient space in the upper floors to realize Harlan's office or corresponding scenes. To rectify the issue, production designer David Crank constructed the office set, which included an adjacent hallway, on soundstages, working closely with Johnson to coordinate the movement of characters with the configuration of the homes and artificial sets.

Principal photography began on October 30, 2018, under the pseudonym Morning Bell, in Maynard, Massachusetts. Filmmakers converted vacant retail space into a laundromat in preparation for the first shoot. Elsewhere in Greater Boston, filming occurred near a MBTA passenger rail station in downtown Natick, a private mid-century modern estate in Lincoln, Canton, Wellesley, Waltham, Medfield, and an unoccupied state-owned facility in Marlborough chosen for its rotund orientation. The Marlborough shoot was the site for exterior scenes at the scorched medical examiner's office, involving pyrotechnics and a group of local firefighters as extras portraying an active firefighting operation. Filming for the project took approximately 38 days, ending on December 20, 2018. Knives Out qualified for a $10 million transferable tax credit on in-state costs from the Massachusetts commonwealth government.

Cinematography
Knives Out was director of photography Steve Yedlin's fifth project with Rian Johnson. The two men storyboarded their visual composition ideas ahead of the principal photography, which did not describe the onscreen universe in depth. Filming used a double-camera setup with two operators, one a longstanding collaborator of Yedlin's. Yedlin described the environment on set as experimental and visually creative. He shot Knives Out in standard 1.85:1 aspect ratio from Alexa Mini cameras equipped with Zeiss Master Prime lenses. The Zeiss Prime's scaling capability supported the film's use of wide-angle shots. The filmmakers believed wider camera lenses emphasized the worldbuilding by showing characters in their surroundings. They also deployed Panavision's PCZ Primo 19-90 and PZW 15-40 zoom lenses as zooming was customary for Johnson's oeuvre. Ultimately, Yedlin and production members adopted action building techniques centered on Robert Altman's cinematic style, through a complex system of whip pans, zooming, and camera dolly movements. Panavision's Hollywood office loaned camera equipment to assist the needs of the production.

Part of Knives Out production was devoted to realizing a specialized process of color grading for the film's visual effects, based on qualitative data collected from Yedlin's field research. The cinematographer's usual strategy prioritized a lookup table (LUT) to augment a film's visual palette, and he observed the science of photochemistry to create his color grading formula. Yedlin collaborated with FotoKem to flesh out properties of halation, gate weave, and granularity. To illuminate interior mansion scenes, Yedlin supplemented sets with an overhead lighting contraption designed from Arri SkyPanels and custom RGBWW strip fixtures—a class of modulated multicolor strip lights—bundled in foam sheets for light diffusion. As well, he relied on computer software and a spectrometer to gauge the sunlight's chromaticity, its specified color quality, and requisite tones to generate the textural variation produced thereof.

Set design
The scriptwriting contained few details about the design of the Thrombey residence, so the estate's clearest vision emerged from conversations that Johnson, Crank, and set decorator David Schlesinger had over aesthetics. The design team were drawn to the Ames Mansion because the original architectural elements had been preserved, endowing sets with an aged quality. Crank and Schlesinger handled the sourcing, then arrangement, of props for interior mansion sets. They located the film's decorative items from a range of businesses, souvenir collectors, and ordinary people in Boston and New York. The script only specified details for a few objects; for the rest, the set decorator used Harlan's imaginary oeuvre of mysteries as inspiration for his souvenirs and knickknacks.

A collection of automata, doll-like mechanical devices that imitate human mannerisms, was chief among the artifacts. The automata were costly, fragile and rare to obtain, requiring thorough scouting from the producers, and additional caveats—transportation, storage, rental fees—complicated the expense. Schlesinger inquired multiple museums and private collectors before contacting the Morris Museum's Murtogh D. Guinness Collection in Morristown, New Jersey, one of the world's largest automata exhibits, but the Morris Museum prohibited all non-exhibition uses of their pieces. They instead directed Schlesinger and his prop-makers to a local restorer, who owned a private collection, to negotiate. Upon approval, the producers hired another local collector to undertake the automata's transportation and installation to and from set. Also present among the background props were large dollhouses, crime scene dioramas, Harlan's library of books, which were designed and arranged by decade, and a stash clock.

Creation of Knives Out most significant prop, the "Wheel of Knives", a throne chair positioned in front of a ringed display of knives, daunted the art department. Although the chair was conceived as a library piece, the script did not explain any correlation to the story, and Crank said developing an established cause was "a long process". The art department abandoned early concepts until they imagined a design with an armature and a chain from which to hang the display.

Music


Rian Johnson pitched Knives Out to composer Nathan Johnson—cousin and another frequent associate—as early as 2009. Their first conversation concerned the context of music in opening scenes, and they sought a score that reflected the film's key events and drama with an abrasive classical sound. Nathan recorded the Knives Out score with an orchestra at Abbey Road Studios in London. To prepare, the composer engaged the production while principal photography was active, visiting the set to forge a premise for melodic cues and motifs. This was an uncommon experience given the standard industry practice for composers is to work in post-production, after filming has finished. "Knives Out! (String Quartet in G Minor)", the opening string quartet theme and Nathan's earliest contribution, served as the impetus for the album.

Nathan and Rian were compelled by an eclectic array of their favorite symphonic movie scores for Knives Out musical direction, such as Death on the Nile, the compositions of Bernard Herrmann, and Lawrence of Arabia (1962). The use of an orchestra distinguishes Knives Out from other films directed by Rian Johnson, which experimented with cheaper, unconventional instruments. It was also Nathan's first large scale orchestral score, being experienced solely with small ensembles. Cut Narrative Records released the soundtrack on November 27, 2019, in tandem with the film's theatrical launch.

Themes
Knives Out has been read as work that investigates class warfare, wealth inequality, immigration, and race in contemporary American society. In interviews organized for the press junket, Bergman, Johnson, and some of the actors expressed candid views of themes common in the Knives Out story, allowing multiple interpretations of the film. Johnson stated the central story neither condemns nor subscribes to a single ideology; rather, it was designed to provoke all moviegoers to contemplate. Moreover, he saw whodunits as well-suited to scrutinize institutional power, a belief influenced by Christie's writings, work he considered indicative of a woman who, while not political, was attuned to British society throughout her life.

Class warfare
Knives Out ranks with other turn-of-the-decade films—such as Ready or Not, Parasite, Hustlers, and Joker (all 2019)—in which class warfare is the unifying theme. The film makes literal class struggle by framing Harlan's death as an explicit tale of good versus evil, Marta emerging as the heroine because of her humanity. Whereas Marta is distraught from the moment Harlan dies, the surviving Thrombeys are fractured by greed, fueled by their stakes in Harlan's publishing fortune. They are ruthless and oblivious of Harlan's demise in a quest for wealth they feel entitled to control and seize by any means. In this sense, it is the Thrombeys, not the elusive suspect per se, who represent the true villains. Yet, in spite of the family's contempt for her and the working class, Marta resists their coercion thanks to her wit and moral convictions. Much emphasis is placed on the alternating points of view of Marta's ordeal to reinforce chasms between the classes. Fast Company Joe Berkowitz argues this device forms the film's class consciousness.

Professor Eugene Nulman posits a Marxist interpretation of Knives Out. Marta is analyzed as an analog for healthcare workers made vulnerable in the COVID-19 pandemic by the failures of neoliberalism, and Nulman contends that the film presents the Thrombey family dynamic as an allegory for capitalism, each relative embodying bourgeois archetypes: the rentier class in Linda, the investor class in Walt, the celebrity class in Joni, the trust fund elite in Ransom, the right-wing establishment in Jacob, and the liberal establishment in Meg. Harlan is the exception because his modest origins, class consciousness, and the family's exploitation of his labor define his circumstance. For this reason, in Nulman's interpretation, Harlan's deliberate suicide and transfer of wealth to Marta are subversive acts that, alongside the Thrombeys' vilification of Marta (mirroring the status quo's counterrevolutionary force), suggest credence to the idea that capitalist exploitation can only be addressed by revolution.

Race
Race was also examined in thematic studies of the film. Knives Out concentrates on a critique of white supremacy and liberal paternalism, comically depicting the Thrombey–Marta relationship through condescending affection and running gags about Marta's country of origin. In his essay for White Supremacy and the American Media, professor Michael Blouin contests the film's analysis of white nationalism. Blouin argues that Knives Out resigns to Jeffersonian democratic ideals—liberal universalism, pragmatic reasoning, and an a priori sense of justice—that buttress a set of racialized assumptions. In doing so, in Blouin's words, all expressed antagonism is neutralized, therefore "depoliticizing a crisis that has so far proven to be resistant to the ideal prescribed by many white liberals."

Narrative structure
In Knives Out, Johnson experiments with narrative structure to generate suspense. The film begins in a traditional whodunit format that is subverted by two tonal shifts. The first shift arranges the plot as a thriller by establishing Marta's reckoning with the manner of Harlan's death, her own implication, and quest to evade the investigation's purview as a cause of conflict, thus framing Blanc as the antagonist. It is in the second shift that, through plausible deniability, Marta's innocence is unequivocal. This posed a significant writing challenge as Johnson intended not only that Marta be a sympathetic character, but also be perceived as justified in her behavior. He was also keen to portray the extremes to which an innocent person might go when threatened with incarceration.

Marketing


Knives Out premiered at the 44th Toronto International Film Festival on September 7, 2019, part of the fest's special presentations lineup. The film then headlined the 14th Fantastic Fest in Austin, Texas as the closing title, before concluding its North American festival itinerary at the Chicago International Film Festival's Centerpiece showcase. In Europe, Knives Out debuted at the 63rd BFI London Film Festival as one of the event's gala entries, held October 2–13, 2019.

Lionsgate supervised the film's advertising campaign. They commenced the promotional cycle in April 2019 with a showcasing preview at CinemaCon, where the first teaser trailer of the film was revealed, followed by another trade show exhibit at CineEurope that June. One critical aspect of the marketing campaign was aggressive social media engagement. Early tactics focused on feel-good messaging, the film's campy humor and Thrombey family enterprises—the lattermost featuring Shannon, Collette, and Curtis in character—through video parodies and mock advertisements developed using website building platforms. The campaign resumed in the weeks following Knives Out late November release, when Ransom's off-white knitted Aran sweater went viral, prompting a brief renaming of the film's official Twitter account to "Chris Evans' Sweater Stan Account" as well as a merchandise giveaway to maximize publicity. Ads reportedly intrigued mostly men but showed strong appeal with women of all ages. For licensed artwork, Johnson unveiled a set of colorful, brooding character posters in September 2019, each with the tagline, "Nothing brings a family together like murder." The director additionally recorded interactive audio commentary to entice repeated business.

Knives Out opened to theaters in North America and the United Kingdom on November 27, 2019. The film's global rollout expanded to China, France, Australia, Russia, and 49 other overseas territories the second week. Its final market was Japan, released on January 31, 2020. Knives Out was seen by industry professionals as a potential hit based on interest sustained from enthusiastic pre-release reviews, the film's unique self-referentiality, and the ensemble's star power, especially Evans, Craig, and Curtis. The success of the film was considered contingent on its ability to attract a broad audience rather than a niche demographic of adults.

Home media
Lionsgate released Knives Out on digital formats on February 7, 2020, and on DVD, Blu-ray and 4K on February 25. Physical copies include deleted scenes; a behind-the-scenes featurette; audio commentary from Johnson, Yedlin, and Noah Segan; an eight-part documentary; advertisements; and previously unaired press interviews. It was the second-best selling DVD and Blu-ray release in its first week of US sales, selling 248,286 copies and earning $4.6 million. By January 2023, the film had sold 1.47 million copies. Knives Out is also available to authenticated Amazon subscribers via the company's Prime Video streaming service.

Box office
Knives Out endured at the box office as a film targeting adults, in a theatrical season saturated with family blockbusters such as Frozen II. It earned $165.4 million in the United States and Canada (52.8% of its earnings) and $147.5 million overseas (47.2%), for a worldwide total of $312.9 million, making it the 29th-highest-grossing film of 2019. Of this figure, $82million was estimated to have been yielded by the MRC–Lionsgate partnership in net profit, factoring in marketing, equipment, royalties, interest, and miscellaneous costs. China was the most lucrative overseas market, and positive press buoyed the film's performance in that country. The United Kingdom, Germany, Australia, and France represented some of the film's largest takings.

In the United States, after securing $2 million from advanced screenings, Knives Out received a wide release across 3,391 theaters. The film benefitted from a five-day tracking period thanks to the Thanksgiving holiday Thursday. This enhanced the first week sum to $41.7 million, ahead of the three-week old Ford v Ferrari and second to Frozen II, which was in its second weekend. Knives Out opening gross nearly doubled the prognosticators' pre-release estimates of $22–25 million. CinemaScore polls conducted during opening night revealed the average grade moviegoers gave the film was A− on an A+ to F scale. Screenings attracted mostly men, and approximately 73% were over 25 years of age, 46% over 35, and 63% white. The second weekend saw Knives Out take another $14.2 million from 3,461 theaters, remaining the number two film, and earnings dropped by about 35% the following week. In the fourth weekend, the film slipped to the number five position with a gross of $6.5 million, its theater count narrowing to slightly above 2,500, though box office figures improved by 50% for the Christmas holiday week (seventh, with $9.7 million). Knives Out remained one of the top ten highest-grossing films for ten weeks, and the theater count stayed above 2,000 at the end of the year. By February 2020, the film's domestic gross topped $159 million.

Overseas, Knives Out overall November 27 week rank was second to Frozen II at $28.3 million. China comprised the largest portion of the earnings with $13.5 million, followed by the United Kingdom ($3.8 million from 632 theaters), Russia ($2 million from 1,451 theaters), Australia ($1.9 million from 282 theaters), and France (third, with $1.5 million from 437 theaters). Knives Out sustained the box office momentum in China and the UK into the second weekend, resulting in a 20% drop in revenue in the latter. After four weeks it had earned $27.9 million in China and $13.7 million in Britain. The film's overseas expansion continued into mid-December, marked by key releases in South Korea (fourth, $1.7 million from 686 cinemas), Italy (third, $1.2 million from 362 cinemas), and Mexico (second, $1.1 million from 871 cinemas). Christmas period saw reinvigorated ticket sales in France, Australia, and Britain, and in Russia, the New Year holiday bolstered the film's box office by 152% over the prior week. Knives Out debuted as the top-grossing movie in Brazil when it premiered the weekend of December 12, earning $1.1 million. On its inaugural weekend elsewhere, the film took $2.7 million in Germany and $665,000 in Austria. Within a month, Knives Out international gross exceeded $100 million.

Critical response
Knives Out opened to widely positive reviews, and, by the end of 2019, was considered one of the year's best films by the American Film Institute, National Board of Review, and the mainstream press in ranked lists. A routinely discussed aspect in the media was the scriptwriting. Knives Out received notice for its unusual plot structure, with reviewers saying the film defied expectations by employing numerous narrative twists and satire of murder mystery tropes. Film critics had high regard for director Rian's comic treatment of a traditional detective story; it was described as "enjoyably, wackily serpentine", with sardonic humor noted for its "sheen of smugness" by The New Yorker. Although comparisons to source material based on tenor, humor, craftmanship, and faithfulness varied among professional opinions, the story's play on perspective among the characters produced favorable responses. According to Stephanie Zacharek for Time, the squabbling between characters who were avaricious, untrustworthy, and ostensibly driven by the same interest, provided the film's most entertaining moments. The writing's political consciousness was cited among the strengths of Knives Out,  although the handling of ideas received occasional disapproval from others, such as The New York Times' Manohla Dargis and Uproxx, for being perceived as too vapid to resonate. The least enthusiastic reviews accused the film of being convoluted, self-indulgent, and too reliant on exposition-dense dialogue to advance the story. In December 2021, Knives Out screenplay was listed number forty-nine on the Writers Guild of America's "101 Greatest Screenplays of the 21st Century (So Far)".

The actors' performances was another major subject in the critiques. The Knives Out ensemble was warmly received, their work praised as "outstanding" and "wildly charismatic", with rapport Vanity Fair ascribed to a shared conviction to the material. Media were somewhat inclined to focus on Daniel Craig and Ana de Armas, but also gave individual notices to Jamie Lee Curtis, Toni Collette, Chris Evans, Don Johnson, Michael Shannon, Christopher Plummer, and Noah Segan for their acting. In particular, critics delighted in Craig's portrayal of an eccentric sleuth in expression and appearance, the actor noted for emanating an "infectious enjoyment" onscreen. De Armas, whose portrayal was described as "superb" and "wonderful", drew similarly strong assessments of her character work from the likes of San Francisco Chronicle Mick LaSalle and The Atlantic, among others, in what was considered a breakout performance. Though the two actors were singled out for further praise because of their onscreen chemistry in conversational scenes, neither they nor their costars were free of criticism. Dissenting opinions judged Craig's Southern accent harshly,  and Uproxx believed de Armas, as a lesser skilled actor, was at odds with the dramatic depth of her role. A few actors were regarded as underused because of the ensemble's large size, which Uproxx argued reduced their interactions to a "constant, white noise-esque drone of overacting".

On the review aggregation website Rotten Tomatoes, Knives Out holds an approval rating of based on  reviews, with an average rating of. The website's critics' consensus reads: "Knives Out sharpens old murder-mystery tropes with a keenly assembled suspense outing that makes brilliant use of writer-director Rian Johnson's stellar ensemble." Metacritic, which uses a weighted average, assigned the film a score of 82 out of 100, based on reviews from 52 critics, indicating "universal acclaim".

Sequels
Johnson was germinating ideas for a Knives Out sequel while the original film was still in theaters in 2019. Lionsgate announced plans to develop the sequel in February 2020, but in March 2021, Netflix actually acquired the rights for two sequels for $469 million. Although the terms of Lionsgate's distribution agreement gave the company bargaining leverage, Johnson and Bergman owned the film's intellectual property and pursued a new distribution deal in the wake of the COVID-19 pandemic, which severely hampered the immediate profit making viability of theaters. Knives Out was followed by Glass Onion: A Knives Out Mystery, released on Netflix on December 23, 2022 after a controversial one week platform theatrical rollout the previous November. In the film, Blanc journeys to tech magnate Miles Bron's (Edward Norton) murder mystery-themed retreat to mingle with his circle of friends, but the event goes awry when two partygoers die under suspicious circumstances. Glass Onion fared well in reviews by the media.

A third film has been in development since 2023. That October, Johnson talked about it in TheWrap: "I obviously couldn't work during the Writers Guild of America strike, and now that it's over, I'm diving in full force, and so it's coming along. I've got the premise, I've got the setting, I've got what the movie is in my head. It's just a matter of writing the damn thing". The film, titled Wake Up Dead Man, is scheduled for release in 2025.