Via Ken Hissner: The following are Olympic Gold Medal winners who became professional world champions. If there are omissions, please comment.
Lennox “Lion” Lewis Gold medalist at the 1988 Seoul Olympics in super heavyweight for Canada. The 1984 Montreal Olympics lost to Tyrell Biggs. 1988 Olympics beat Riddick Bowe. WBC, WBA, IBF and IBO Champion from West Ham, London, UK. Professional record: 41-2-1 (32).
Wladimir “Dr. Steelhammer” Klitschko Super Heavyweight 1996 Atlanta Olympics gold medalist for Ukraine. WBA, WBO, IBF and IBO champion from Kiev, Ukraine. Professional record: 64–5 (53).
Anthony “AJ” Joshua Gold medalist at the 2012 London Olympics, super heavyweight for Great Britain. The WBA, WBO, IBF and IBO champion is from Watford, Hertfordshire, UK. Professional record: 24-2 (22).
Floyd Patterson 1952 Helsinki middleweight Olympic gold medal for the United States. NBA and NYSAC Heavyweight Champion from Brooklyn, NY.
“Smokin” Joe Frazier Gold medalist at the 1964 Tokyo Olympics in heavyweight for the United States. Lost to Buster Mathis twice. NYSAC, WBC and WBA Champion from Philadelphia, PA. Professional record: 32-4-1 (27).
“Big” George Foreman Gold medalist at the 1968 Mexican Olympics in heavyweight for the United States. WBC, WBA and IBF Champion from Houston, Texas, USA. Professional record: 76-5 (68).
Evander “The Real Deal” Holyfield’s 1984 Montreal Olympics gold medal for the United States. WBA, WBC and IBF, WBA, WBC and IBF heavyweight champion from Atlanta, Georgia. Professional record: 44-10-2 (29).
Cassius Clay Light Heavyweight Gold medalist at the 1960 Rome Olympics for the United States. Cassius Clay, aka Muhammad “The Greatest One” Ali. NYSAC, WBC and WBA Heavyweight Champion from Louisville, KY. Professional record: 56-5 (37).
Leon “Neon” Spinks Gold medalist at the 1976 Montreal Olympics in lightweight for the United States. WBA and WBC heavyweight champion from St. Louis, MO. Professional record: 26-17-3 (14).
Michael “Jinx” won the 1976 Montreal Olympics gold medal in middleweight for the United States. WBA, WBC and IBF Light Heavyweight Champion. The IBF Heavyweight Champion from St. Louis, MO. Professional record: 31-1 (21).
Mate Parlov Light Heavyweight 1972 Munich Olympics gold medalist for Croatia. WBC heavyweight champion from Pula, Croatia. Professional record: 24-3-2 (12).
Slobodan Kacar Light Heavyweight 1980 at the Moscow Olympics for Yugoslavia. IBF Light Heavyweight Champion from Bosnia and Herzegovina and Belgrade, Serbia. Professional record: 22-2 (12).
Vassili “The Tiger” Jirov 1996 Atlanta Olympics gold medalist in lightweight for Kazakhstan. Defeat Sven Ottke, Julio Cesar Gonzalez and Antonio Tarver. IBF Cruiserweight Champion from Balqash, KAZ and Scottsdale, AZ. Professional record: 38-3-1 (32).
Andre “SOG” Ward Gold medalist at the 2004 Athens Olympics in light heavyweight for the United States. WBA and WBC Super Middleweight Champion. WBO, WBA and IBF lightweight champion from Oakland, CA. Professional record: 32-0 (16).
Henry “Gentleman” Maske 1988 Seoul Olympics middleweight gold medalist for East Germany. Beat Sven Ottke and Jose Gomez. IBF lightweight champion from Cologne, Germany. Professional record: January 31 (11).
James “Chunky” DeGale 2008 Beijing Olympics middleweight gold medalist for Great Britain. Defeat Shawn Porter. The IBF Super Middleweight Champion from St. Albans, Hertfordshire, UK. Professional record: 25-3-1 (15).
Ryota Murata Gold medalist at the 2012 London Olympics in middleweight for Japan. Defeat Esquiva Falcao twice. WBA middleweight champion from Tokyo, Japan. Professional record: 16-2 (13).
Frank Tate Light Middleweight Gold medalist at the 1984 Los Angeles Olympics for the United States. Beating Reggie Johnson won and lost to Michael Nunn. IBF Middleweight Champion from Houston, Texas. Professional record: 41-5 (24).
David “American Dream” Reid Gold medalist at the 1988 Atlanta Olympics in light welterweight for the United States. WBA lightweight middleweight champion from Philadelphia, PA. Professional record: 17-2 (7).
Giovanni “Nino” Benvenutti Olympic gold medal in Rome in 1960 for Italy. WBA and WBC middleweight champion and WBA and WBC middleweight champion from Slovenia and Trieste. Friuli-Venezia Giulia, Italy. Professional record: 82-7-1 (35).
Mark Breland Gold Medalist at the 1984 Montreal Olympics for the United States. WBA Welterweight Champion from New York, NY. Professional record: 35-3-1 (25).
Daniyar Yeleussinov 2016 Rio de Janeiro Olympics gold medal for Kazakhstan. IBO Welterweight Champion from Kayindy, KAZ and Miami, Florida. Professional record: 11-0 (6).
Montreal Olympics Gold Medalist “Sugar” Ray Leonard for the United States. WBC and WBA Welterweight, WBA Light Middleweight, WBC Middleweight, WBC Super Middleweight and WBC Light Heavyweight championships from Palmer Park, Maryland. Professional record: 36-3-1 (25).
Pernell “Sweet Pea” Whitaker 1984 Montreal Olympics lightweight gold medalist for the United States. WBA, WBC and IBF Lightweight, IBF Light Welterweight, WBC Welterweight and WBA Light Middleweight championships from Norfolk, VA. Professional record: 40-4-1 (17).
Meldrick “The Kid” Taylor Featherweight Olympics 1984 Montreal
Gold Medal for USA. IBF lightweight champion and WBA Welterweight champion from Philadelphia, PA. Professional record: 38-8-1 (20).
Giovanni “Flash” Parisi Gold medalist at the 1988 Seoul Olympics in Featherweight for Italy. WBO Welterweight and WBO Light Welterweight Champion from Voghera, Lombardia, Italy. Professional record: 41-5-1 (29).
Vasyl “Loma” Lomachenko Gold medalist at the 2008 London Olympics Featherweight and 2012 Beijing Lightweight Games from Ukraine. WBO Featherweight, WBO Super Featherweight and WBO, WBA and WBC lightweight champion from Bilhorod- Dinistrovskyi, Ukraine. Professional record: 16-2 (11).
Patrizio Oliva Lightweight Welterweight 1980 Moscow Olympics Gold Medalist for Italy and WBA Welterweight Welterweight Champion from Napoli, Campania, Italy. Professional record: 57-2 (20).
Leo Randolph Flyweight 1976 Montreal Olympics gold medalist for the United States. WBA Super Bantamweight Champion from Spanaway, Washington.
Johnny “Bump City” Bumphus 139 lb 1984 Moscow Olympics gold medalist for the United States. WBA Light Welterweight Champion from Nashville, TN. Professional record 29-2 (20).
“King” Kennedy McKinney Bantamweight 1988 Seoul Olympics gold medalist for USA and IBF and WBO Super Bantamweight champion from Las Vegas, Nevada. Professional record: 36-6-1 (19).
Joel “El Cepillo” Casamayor Bantamweight 1992 Barcelona Olympics gold medalist for Cuba and WBA and WBC lightweight lightweight champion from Guantanamo, Cuba and Miramar, Florida. Professional record: 38-6-1 (22).
Oscar “Golden Boy” De La Hoya Olympic Lightweight 1992 Barcelona Olympics Gold Medalist for USA and WBO, WBO and IBF Lightweight, WBC Welterweight, WBC Welterweight and WBC and WBA Light Welterweights and WBO middleweight champion from Los Angeles, California. Professional record: 39-6 (30).
Pascual “El Leon Mendocino Terrier” Perez Gold medalist at the 1948 London Olympics for Argentina and world Flyweight champion from Ciudad Mendoza, Argentina. Professional record: 84-7-1 (57).