2021 French Open – Men's singles

Novak Djokovic defeated Stefanos Tsitsipas in the final, 6–7(6–8), 2–6, 6–3, 6–2, 6–4 to win the men's singles tennis title at the 2021 French Open. It was his second French Open title and 19th major title overall. With this victory, he became the first man to achieve the double career Grand Slam in the Open Era, and the first player in the Open Era to win a major after coming back from two sets to love down in two matches during the same major. Tsitsipas became the first Greek player to reach a major final. It also marked the second consecutive year a man trailed by two sets in a major final yet rallied to win, following Dominic Thiem's victory at the 2020 US Open.

Rafael Nadal was the four-time defending champion, but lost to Djokovic in a 4 hour and 11 minute epic semifinal. Nadal's defeat marked only his third loss out of 108 French Open matches, including his first loss in 14 semifinal appearances at the tournament. It also marked the first time that Nadal lost a match at the French Open after taking the opening set, and the first French Open where a player defeated Nadal and went on to win the tournament. In winning this match, Djokovic became the first (and only) man ever to defeat Nadal two times at the French Open.

Djokovic and Daniil Medvedev were in contention for the world No. 1 ranking; Djokovic retained the ranking after Medvedev lost in the quarterfinals.

Nadal and Roger Federer were attempting to win a record 21st major title and become the outright leader in the men's singles major tally. Federer, like Djokovic, was attempting to become the first man in the Open Era to achieve the double career Grand Slam in what would prove to be his final French Open appearance. This was the first time in major history that Djokovic, Federer, and Nadal, the three most successful men's singles major champions of all time, were in the same half of the main draw. After both reached the semifinals, Djokovic and Nadal met for a record-extending 58th time in the Open Era, with Djokovic emerging victorious in four sets.

For the first time in the Open Era, no French players reached the third round. This tournament also marked the last time that any Grand Slam featured Nadal, Federer and Djokovic together, thus marking an end of the "Big Three" era. Thiem's first-round defeat guaranteed a new French Open finalist from the bottom half of the draw; Tsitsipas ultimately emerged as that finalist. Carlos Alcaraz became the youngest player since Djokovic in 2005 to win a match at the French Open, and was also the youngest player to reach the third round at the tournament since Andrei Medvedev in 1992. This was the first time since 2004 that a French Open men's singles final went to five sets; on that occasion, Gastón Gaudio also came from two sets down to win the title.

Seeds
• 🇷🇸 Novak Djokovic (champion)

• 🇷🇺 Daniil Medvedev (quarterfinals)

• 🇪🇸 Rafael Nadal (semifinals)

• 🇦🇹 Dominic Thiem (first round)

• Stefanos Tsitsipas (final)

• 🇩🇪 Alexander Zverev (semifinals)

• 🇷🇺 Andrey Rublev (first round)

•  Roger Federer (fourth round, withdrew)

• 🇮🇹 Matteo Berrettini (quarterfinals)

• 🇦🇷 Diego Schwartzman (quarterfinals)

• 🇪🇸 Roberto Bautista Agut (second round)

• 🇪🇸 Pablo Carreño Busta (fourth round)

• 🇧🇪 David Goffin (first round)

• 🇫🇷 Gaël Monfils (second round)

• 🇳🇴 Casper Ruud (third round)

• 🇧🇬 Grigor Dimitrov (first round, retired)

• 🇨🇦 Milos Raonic (withdrew)

• 🇮🇹 Jannik Sinner (fourth round)

• 🇵🇱 Hubert Hurkacz (first round)

• 🇨🇦 Félix Auger-Aliassime (first round)

• 🇦🇺 Alex de Minaur (second round)

•  Cristian Garín (fourth round)

• 🇷🇺 Karen Khachanov (second round)

• 🇷🇺 Aslan Karatsev (second round)

• 🇬🇧 Dan Evans (first round)

• 🇮🇹 Lorenzo Sonego (first round)

• 🇮🇹 Fabio Fognini (third round)

•  Nikoloz Basilashvili (second round)

• 🇫🇷 Ugo Humbert (first round)

• 🇺🇸 Taylor Fritz (second round)

• 🇺🇸 John Isner (third round)

• 🇺🇸 Reilly Opelka (third round)

Seeded players
The following are the seeded players. Seedings are based on ATP rankings as of 24 May 2021. Rankings and points before are as of 31 May 2021. Because the tournament was moved a week, points of the week of 10 June 2019 include results from Stuttgart and 's-Hertogenbosch.

As announced by the ATP in March 2021, tournaments from 4 March to 4 August 2019 points due to COVID ranking adjustments will count 50%, including their 2020 points whichever is greater. 2019 points which are higher will still be dropped as normal. Accordingly, the higher of each player's 2019 or 2020 points will be replaced by his 2021 points at the end of the tournament. Note that this is a different ranking adjustment system than the one being used by the WTA for the women's event.

† The player did not qualify for the tournament in 2019. Therefore, this represents his points from the 2019 ATP Challenger Tour.

Withdrawn players
The following players would have been seeded, but withdrew before the tournament began.

Wild cards
The following players were awarded wild cards into the main draw. • 🇫🇷 Grégoire Barrère

• 🇫🇷 Benjamin Bonzi

• 🇫🇷 Mathias Bourgue

• 🇫🇷 Arthur Cazaux

• 🇫🇷 Enzo Couacaud

• 🇫🇷 Hugo Gaston

• 🇦🇺 Christopher O'Connell

• 🇫🇷 Arthur Rinderknech

Protected ranking
• 🇩🇪 Philipp Kohlschreiber (96)

• Lu Yen-hsun (71)

• 🇵🇱 Kamil Majchrzak (105)

Qualifiers
• 🇪🇸 Carlos Alcaraz

• 🇺🇸 Jenson Brooksby

• 🇯🇵 Taro Daniel

• 🇺🇸 Bjorn Fratangelo

• 🇨🇴 Daniel Elahi Galán

• 🇮🇹 Alessandro Giannessi

• 🇺🇿 Denis Istomin

• Henri Laaksonen

• 🇩🇪 Maximilian Marterer

• 🇺🇸 Mackenzie McDonald

• 🇩🇪 Oscar Otte

• 🇷🇺 Roman Safiullin

• 🇪🇸 Carlos Taberner

• 🇪🇸 Mario Vilella Martínez

•  Botic van de Zandschulp

• 🇪🇸 Bernabé Zapata Miralles

Lucky losers
• 🇦🇷 Francisco Cerúndolo

• 🇩🇪 Peter Gojowczyk

Withdrawals
• 🇦🇺 Nick Kyrgios (57) → replaced by 🇦🇷 Facundo Bagnis (103)
 * Before the tournament

• Borna Ćorić (26) → replaced by 🇸🇰 Andrej Martin (104)

• 🇬🇧 Kyle Edmund (69) → replaced by 🇪🇸 Roberto Carballés Baena (105)

•  Stan Wawrinka (20) → replaced by 🇵🇱 Kamil Majchrzak (105 PR)

• 🇭🇺 Attila Balázs (102) → replaced by  João Sousa (106)

• 🇨🇦 Vasek Pospisil (64) → replaced by  Kevin Anderson (107)

• 🇨🇦 Denis Shapovalov (13)  → replaced by 🇯🇵 Yasutaka Uchiyama (108)

• 🇨🇦 Milos Raonic (19) → replaced by 🇦🇷 Francisco Cerúndolo (LL)

• 🇦🇺 John Millman (44) → replaced by 🇩🇪 Peter Gojowczyk (LL)

• Roger Federer
 * During the tournament

Retirements
• 🇧🇬 Grigor Dimitrov

• Henri Laaksonen

• 🇮🇹 Lorenzo Musetti