Twenty-one Number One Hits: The Ultimate Collection

21 #1 Hits: The Ultimate Collection is an album by Buck Owens and his Buckaroos, released in 2006. Released shortly after his death, it is a single-disc compilation containing all of Owens' number one chart hits.

Reception
In his Allmusic review, critic Stephen Thomas Erlewine wrote "...there is no other single-disc Buck CD that comes as close to offering as much of his best in one disc as 21 #1 Hits: The Ultimate Collection, and it's nice to finally have such a collection in his catalog after such a long wait."

Track listing
All songs by Buck Owens unless otherwise noted.
 * 1) "Act Naturally" (Voni Morrison, Johnny Russell) – 2:22
 * 2) "Love's Gonna Live Here" – 2:02
 * 3) "Streets of Bakersfield" [Dwight Yoakam & Buck Owens] (Homer Joy) – 2:49
 * 4) "I've Got a Tiger By the Tail" (Harlan Howard, Owens) – 2:15
 * 5) "My Heart Skips a Beat" – 2:27
 * 6) "Together Again" – 2:27
 * 7) "I Don't Care (Just as Long as You Love Me)" – 2:10
 * 8) "Before You Go" (Owens, Don Rich) – 2:11
 * 9) "Only You (Can Break My Heart)" –  2:21
 * 10) "Buckaroo" (Bob Morris) – 2:00
 * 11) "Waitin' in Your Welfare Line" (Owens, Rich, Nat Stuckey) – 2:19
 * 12) "Think of Me" (Estella Olson, Rich) – 2:17
 * 13) "Open Up Your Heart" – 2:29
 * 14) "Where Does the Good Times Go" – 2:20
 * 15) "Sam's Place" (Owens, Red Simpson) – 2:00
 * 16) "Your Tender Loving Care" – 2:46
 * 17) "How Long Will My Baby Be Gone" – 2:14
 * 18) "Who's Gonna Mow Your Grass" – 2:23
 * 19) "Tall Dark Stranger" – 3:00
 * 20) "Made in Japan" (Bob Morris, Faye Morris) – 2:42
 * 21) "Johnny B. Goode" (Chuck Berry) – 2:23

Personnel
Production notes
 * Buck Owens – guitar, vocals, harmony vocals
 * Don Rich – guitar, fiddle, harmony vocals
 * Doyle Holly – guitar, bass, background vocals
 * Flaco Jiménez – accordion
 * The Jordanaires – background vocals
 * Pete Anderson – guitar
 * Albert "Al Bruno" Bruneau – guitar
 * James Burton – guitar
 * Willie Cantu – drums, tambourine
 * Mel King – drums
 * Doyle Curtsinger – bass
 * Jeff Donavan – drums
 * Skip Edwards – piano
 * Donald Frost – bass
 * Tom Brumley – pedal steel guitar
 * Jay Dee Maness – pedal steel guitar
 * Jay McDonald – pedal steel guitar
 * Bob Morris – bass
 * Kenny Pierce – bass
 * Ken Presley – drums
 * Taras Prodaniuk – bass
 * Don Reed – fiddle
 * Jelly Sanders – guitar
 * Jim Shaw – organ
 * Red Simpson – guitar
 * Mel Taylor – drums
 * Jerry Wiggins – drums
 * Dwight Yoakam – guitar, vocals
 * Ken Nelson – producer
 * Pete Anderson – producer
 * Jim Shaw – executive producer
 * James Austin – project Supervisor
 * Dave Schultz – remastering
 * Mathieu Bitton – art direction, design
 * Patrick Mulligan – discographical annotation
 * Gary Peterson – discographical annotation
 * Rich Kienzle – liner notes
 * Sheryl Farber – editorial supervision
 * Alan Fletcher – project supervisor
 * Mimi Miraflor – project assistant
 * Steve Woolard – project assistant
 * Becky Wagner – project assistant