Undefeated Boxers: Perfect Career Records

Floyd Mayweather and Rocky Marciano are boxing’s two most celebrated undefeated champions, retiring with perfect records of 50-0 and 49-0. Marciano remains the only heavyweight champion in history to walk away without a single defeat, while Mayweather edged past his win total by fighting once more in 2017 to finish at 50.

A perfect record is boxing’s rarest achievement, because a single loss can end it at any moment across a long career. The fighters who manage it join an exclusive club, though comparing them means weighing different weight classes, eras and styles of matchmaking. Here is a leaderboard of the sport’s most notable unbeaten world champions, the records behind them, and the debates they inspire. All figures are as of the 2025 season.

The headliners: Mayweather and Marciano

Floyd Mayweather built his 50-0 record across five weight classes and more than two decades, blending defensive genius with shrewd career management. His final bout, a 2017 win over UFC star Conor McGregor, pushed him past the symbolic 49 to a round 50 victories with no losses.

Rocky Marciano’s 49-0 carries a distinction Mayweather’s cannot: it was compiled at heavyweight, and he remains the only champion in the division’s history to retire unbeaten. Marciano won 43 of his fights by knockout, a punishing pace, and chose to retire in 1956 with his record intact rather than risk it. The two men anchor almost every conversation about perfect careers.

The full leaderboard of notable unbeaten champions

The table below lists some of boxing’s most famous world champions who retired unbeaten, or remain unbeaten, ranked by career wins. Active fighters are noted.

Rank	Record	Boxer	Division(s)
1	51-0-1	Ricardo López	Minimumweight
2	50-0	Floyd Mayweather	Super feather to light middleweight
3	49-0	Rocky Marciano	Heavyweight
4	46-0	Joe Calzaghe	Super middleweight / light heavyweight
5	41-0*	Terence Crawford	Lightweight to super welterweight
6	34-0	Sven Ottke	Super middleweight
7	32-0	Andre Ward	Super middleweight / light heavyweight
8	29-0*	Naoya Inoue	Bantamweight / super bantamweight
9	26-0-1	Terry Marsh	Light welterweight
10	24-0*	Oleksandr Usyk	Cruiserweight / heavyweight

*Active fighter as of the 2025 season; record still open and win total still climbing. Records show wins-losses-draws.

The list spans weight classes and generations, from the minimumweight mastery of Ricardo López to the modern heavyweight reign of Oleksandr Usyk. What unites them is the absence of a loss, the single fact that defines a perfect career.

Ricardo López and Joe Calzaghe: perfect at every level

Ricardo López, Mexico’s minimumweight great, retired with the most wins of any modern champion without a defeat, 51, spoiled only by one technical draw. Joe Calzaghe, the Welsh super middleweight, went 46-0 and beat a line of elite opponents before retiring on top. Neither name carries the mainstream fame of Mayweather, but among purists both rank with the finest unbeaten champions ever.

The active chase: Crawford, Usyk and Inoue

Several current stars are writing their own unbeaten stories. Terence Crawford has won world titles across multiple divisions without a loss, Oleksandr Usyk has unified titles at cruiserweight and heavyweight while staying perfect, and Japan’s Naoya Inoue has dominated the lower weights. Because all three are still fighting, their records could change with a single result, which is exactly what makes a perfect career so precious.

Why these records matter

An unbeaten record is boxing’s purest measure of invincibility, and it explains why Mayweather and Marciano remain reference points decades apart. Marciano’s heavyweight distinction and Mayweather’s 50th win give the debate no clean answer, which is part of its appeal. For a broader ranking of the sport’s finest, see our list of the greatest boxers of all time, and for how these perfect records are earned round by round, our explainer on how boxing scoring works.

The short version: Floyd Mayweather (50-0) and Rocky Marciano (49-0) are boxing’s most famous undefeated champions, with Marciano the only heavyweight ever to retire unbeaten. Ricardo López (51-0-1) and Joe Calzaghe (46-0) belong in the same conversation. As of the 2025 season, Terence Crawford, Oleksandr Usyk and Naoya Inoue are carrying perfect records forward.

Frequently asked questions

Which boxers retired undefeated?+

Floyd Mayweather (50-0) and Rocky Marciano (49-0) are the most famous boxers to retire undefeated. Others include Ricardo López (51-0-1), Joe Calzaghe (46-0), Sven Ottke (34-0) and Andre Ward (32-0). Marciano is the only heavyweight champion ever to retire without a loss. All figures are as of the 2025 season.

Is Floyd Mayweather or Rocky Marciano the more impressive record?+

It is a genuine debate. Rocky Marciano went 49-0 as a heavyweight, the only champion in the division's history to retire unbeaten, and won most of his fights by knockout. Floyd Mayweather finished 50-0 across five weight classes over a longer era with tougher matchmaking scrutiny. Marciano holds the historic distinction; Mayweather holds the higher win total.

Has any boxer retired with more than 50 wins and no losses?+

Yes. Ricardo López, the Mexican minimumweight great, retired with a record of 51-0-1, the lone blemish being a technical draw. Some early-1900s fighters also compiled long unbeaten records in an era of no-decision bouts, but among modern world champions López holds the most wins without a defeat.

Which active boxers are still undefeated?+

As of the 2025 season, Terence Crawford and Oleksandr Usyk are among the most prominent world champions with unbeaten professional records, and Japan's Naoya Inoue has also stayed undefeated across multiple weight classes. Because they are still fighting, their perfect records remain at risk and their win totals are still climbing.

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