Middleweight
| Number | Champion | Reign |
|---|---|---|
| 1 | Marcel Thil | 1933 - September 23, 1937 (Vacated title) |
| 2 | Freddie Steele (Awarded title) | September 23, 1937 - 1938 (Stripped) |
| 3 | Tony Zale (beat Georgie Abrams) | November 28, 1941 - July 16, 1947 |
| 4 | Rocky Graziano | July 16, 1947 - June 10, 1948 |
| 5 | Tony Zale | June 10, 1948 - September 21, 1948 |
| 6 | Marcel Cerdan | September 21, 1948 - June 16, 1949 |
| 7 | Jake LaMotta | June 16, 1949 - February 14, 1951 |
| 8 | Sugar Ray Robinson | February 14, 1951 - July 10, 1951 |
| 9 | Randy Turpin | July 10, 1951 - September 12, 1951 |
| 10 | Sugar Ray Robinson | September 12, 1951 - December 18, 1952 (Retired) |
| 11 | Carl Olson (beat Randy Turpin) | October 21, 1953 - December 9, 1955 |
| 12 | Sugar Ray Robinson | December 9, 1955 - January 2, 1957 |
| 13 | Gene Fullmer | January 2, 1957 - May 1, 1957 |
| 14 | Sugar Ray Robinson | May 1, 1957 - January 22, 1960 |
| 15 | Paul Pender | January 22, 1960 - July 11, 1961 |
| 16 | Terry Downes | July 11, 1961 - April 7, 1962 |
| 17 | Paul Pender | April 7, 1962 - May 7, 1963 (Retired) |
| 18 | Dick Tiger (Awarded title by The Ring) | May 7, 1963 - December 7, 1963 |
| 19 | Joey Giardello | December 7, 1963 - October 21, 1965 |
| 20 | Dick Tiger | October 21, 1965 - April 25, 1966 |
| 21 | Emile Griffith | April 25, 1966 - April 17, 1967 |
| 22 | Nino Benvenuti | April 17, 1967 - September 29, 1967 |
| 23 | Emile Griffith | September 29, 1967 - March 4, 1968 |
| 24 | Nino Benvenuti | March 4, 1968 - November 7, 1970 |
| 25 | Carlos Monzón | November 7, 1970 - August 29, 1977 (Retired) |
| 26 | Rodrigo Valdez (beat Bennie Briscoe) | November 5, 1977 - April 22, 1978 |
| 27 | Hugo Corro | April 22, 1978 - June 30, 1979 |
| 28 | Vito Antuofermo | June 30, 1979 - March 16, 1980 |
| 29 | Alan Minter | March 16, 1980 - September 27, 1980 |
| 30 | Marvelous Marvin Hagler | September 27, 1980 - April 6, 1987 |
| 31 | Sugar Ray Leonard | April 6, 1987 - (retired, then moved up to Super Middleweight) |
| 32 | Sumbu Kalambay (Awarded title by The Ring) | July 6, 1988 - March 2, 1989 (The Ring ceased publication for 7 months) |
| 33 | Bernard Hopkins (beat Felix Trinidad) | September 29, 2001 - July 16, 2005 |
| 34 | Jermain Taylor | July 16, 2005 - September 29, 2007 |
| 35 | Kelly Pavlik | September 29, 2007 – April 17, 2010 |
| 36 | Sergio Gabriel Martínez | April 17, 2010 – present |
Read more about this topic: List Of The Ring World Champions