Undefeated heavyweight world champion, Boxing
- Who
- Unknown
- What
- 49 total number
- Where
- United States
- When
- 01 January 0001
Rocky Marciano (USA) (b. Rocco Francis Marchegiano) (1923-69) is the only world champion at any weight to have won every fight of his entire completed professional career, from 17 March 1947-21 September 1955 (he announced his retirement on 27 April 1956); 43 of his 49 fights were by knock-outs or stoppages.