List of undefeated boxing world champions
This is a list of world champions in professional boxing who retired undefeated, either during or after a title reign(s). It excludes current titleholders.

List of undefeated boxing world champions

Section Title:
Table Section Text: This is a list of world champions in professional boxing who retired undefeated, either during or after a title reign(s). It excludes current titleholders.

Boxer	Record	Weight class	Title(s)	Championship years	Title defenses	Notes

United States Jimmy Barry	59–0–9 (2)	Bantamweight	World	1894–1899	6 (3 draws)

United Kingdom Joe Calzaghe	46–0–0 (0)	Super middleweight	WBO	1997–2008	21	Vacated title to move up to light heavyweight.

IBF	2006	1	Vacated title to fight Peter Manfredo Jr. instead of #1 contender Robert Stieglitz.

The Ring, lineal	2006–2008	3	Vacated titles to move up to light heavyweight.

WBA, WBC	2007–2008	0

Light heavyweight	The Ring	2008	1	Retired and vacated title.

South Korea Kim Ji-won	16–0–2 (0)	Super bantamweight	IBF	1985–1986	4

Romania Mihai Leu	28–0–0 (0)	Welterweight	WBO	1997	1	Retired from boxing due to an injury.

Mexico Ricardo López	51–0–1 (0)	Minimumweight	WBC	1990–1998	22	Vacated title to move up to light flyweight.

WBO	1997–1998	0	Unified WBC and WBO titles. Stripped of WBO title for saying he wanted to give the belt to his father.

WBA	1998	0	Vacated title to move up to junior flyweight.

Light flyweight	IBF	1999–2002	2

United States Rocky Marciano	49–0–0 (0)	Heavyweight	World	1952–1956	6

United Kingdom Terry Marsh	26–0–1 (0)	Light welterweight	IBF	1987	1	Retired from boxing due to epilepsy.

United States Floyd Mayweather Jr.	50–0–0 (0)	Super featherweight	WBC	1998–2002	8	Vacated title to move up to lightweight.

Lightweight	WBC	2002–2004	3	Vacated title to move up to light welterweight.

Light welterweight	WBC	2005–2006	0	Vacated title to move up to welterweight.

Welterweight	WBA, WBC	2006–2008, 2011–2015	8	Retired at 49–0 in 2015; returned in 2017 for non-title McGregor fight and then retired again.

Light middleweight	WBA, WBC	2007, 2012–2015, 2017	2

Republic of Ireland Jack McAuliffe	30–0–5 (1)	Lightweight	World	1886–1893	7–0–2 (0)

Germany Sven Ottke	34–0–0 (0)	Super middleweight	IBF	1998–2004	21

WBA	2003–2004	4	Defended IBF title and defeated WBA champion to become WBA Super champion.

Russia Dmitry Pirog	20–0–0 (0)	Middleweight	WBO	2010–2012	3	Retired from boxing due to chronic back injuries.

Namibia Harry Simon	31–0–0 (0)	Light middleweight	WBO	1998–2001	4	Vacated title to move up to middleweight.

Middleweight	WBO	2002	0	Won WBO interim middleweight title in 2001 and the outright title in 2002. Stripped of title at 22–0 when he was unable to defend it due to injuries suffered in a car crash.

Thailand Pichit Sitbangprachan	24–0–0 (0)	Flyweight	IBF	1992–1994	5	Retired at 21–0 and then made a comeback.

Venezuela Edwin Valero	27–0–0 (0)	Super featherweight	WBA	2006–2008	4	Vacated title to move up to lightweight.

Lightweight	WBC	2009–2010	2	Vacated title to move up to light welterweight. Committed suicide after allegedly killing his wife in 2010.

United States Andre Ward	32–0–0 (0)	Super middleweight	WBA	2009–2015	6	Vacated titles in 2015 to move up to light heavyweight.

WBC, The Ring, lineal	2011–2015	1 (WBC), 2 (The Ring, lineal)

Light heavyweight	WBA, WBO, The Ring, lineal	2016–2017	1 (WBA, IBF, WBO), 0 (The Ring, lineal)

Sentence(s)

Edwin Valero was an undefeated former world champion in two weight classes at the time of his death, having held the WBA super featherweight title from 2006 to 2008 and the WBC lightweight title from 2009 to 2010.
Edwin Valero was an undefeated world champion in two weight classes, having held the WBA super featherweight title from 2006 to 2008 and the WBC lightweight title from 2009 to 2010.
Edwin Valero was an undefeated former world champion in two weight classes at the time of his death, having held the WBA super featherweight title from 2006 to 2008 and the WBC lightweight title from 2009 to 2010.

final_sentence: Edwin Valero was an undefeated former world champion in two weight classes at the time of his death, having held the WBA super featherweight title from 2006 to 2008 and the WBC lightweight title from 2009 to 2010.
final_sentence: Edwin Valero was an undefeated world champion in two weight classes, having held the WBA super featherweight title from 2006 to 2008 and the WBC lightweight title from 2009 to 2010.
final_sentence: Edwin Valero was an undefeated former world champion in two weight classes at the time of his death, having held the WBA super featherweight title from 2006 to 2008 and the WBC lightweight title from 2009 to 2010.