Marco Antonio Barrera Tapia is a Mexican former professional boxer who competed from 1989 to 2011. He held multiple world championships in three weight classes between 1995 and 2007, from super bantamweight to super featherweight.
Jorge Armando Arce Armenta, best known as Jorge Arce, is a Mexican former professional boxer who competed from 1996 to 2014. He is a multiple-time world champion, and the second boxer from Mexico to win world titles in four weight divisions. In a storied career, Arce held the WBO light flyweight title from 1998 to 1999; the WBC and lineal light flyweight titles from 2002 to 2004; the WBO super flyweight title in 2010; the WBO junior featherweight title in 2011; and the WBO bantamweight title from 2011 to 2012. Additionally he held the WBC interim flyweight title from 2005 to 2006, the WBA interim super flyweight title from 2008 to 2009, and challenged once for the WBC featherweight title in his final fight in 2014.
Daniel Gregorio "Danny" Romero Jr. is an American former professional boxer who competed between 1992 and 2006. He is a world champion in two weight classes, having held the IBF flyweight title from 1995 to 1996 and the IBF junior bantamweight title from 1996 to 1997.
Vakhtang "Vic" Darchinyan is an Armenian former professional boxer who competed from 2000 to 2017. He held multiple world championships in two weight classes, including the IBF flyweight title from 2004 to 2007; and the WBA, WBC, IBF, and lineal super-flyweight titles between 2008 and 2010. Additionally, he held a record four IBO titles at flyweight, super-flyweight, and twice at bantamweight between 2005 and 2011. A southpaw with a highly unique fighting style and formidable punching power, Darchinyan became the first Armenian boxer to win a world title in 2004.
Marcellus Joseph Johnson, better known as Mark "Too Sharp" Johnson, is an American former professional boxer who competed from 1990 to 2006. He is a three-time world champion in two weight classes, having held the IBF flyweight title from 1996 to 1999; the IBF junior bantamweight title from 1999 to 2000; and the WBO junior bantamweight title from 2003 to 2004.
Duke McKenzie is a British former professional boxer who competed from 1982 to 1998. He is a three-weight world champion, having held the IBF flyweight title from 1988 to 1989; the WBO bantamweight title from 1991 to 1992; and the WBO junior-featherweight title from 1992 to 1993. At regional level he held the British flyweight title from 1985 to 1988; the European flyweight title from 1986 to 1988; and the British featherweight title from 1993 to 1994. After retiring from the sport, McKenzie has worked as a boxing commentator for broadcaster ITV.
Nonito Gonzales Donaire Jr. is a Filipino American professional boxer. He has held multiple world championships in four weight classes from flyweight to featherweight, and is the oldest boxer in history to win a bantamweight world title, as well as being the first three-time champion in that weight class. Donaire has also held world championships in three consecutive decades: the 2000s, 2010s and 2020s, being the sixth boxer to do so after Evander Holyfield, Manny Pacquiao, Bernard Hopkins, Érik Morales, and Floyd Mayweather Jr.
Geronimo "Gerry" J. Peñalosa is a Filipino former professional boxer who competed from 1989 to 2010. He is a two-weight world champion, having held the WBC super-flyweight title from 1997 to 1998, and the WBO bantamweight title from 2007 to 2009. Originally from the city of San Carlos, Negros Occidental, Peñalosa currently resides in Manila. He was trained mainly by Freddie Roach, and went on to become a boxing trainer himself after retirement. Peñalosa's older brother, Dodie Boy Peñalosa, is also a former boxer and world champion.
Donnie Liboon Nietes is a Filipino professional boxer. He is a world champion in four weight-classes, having previously held the WBO mini-flyweight title from 2007 to 2011; the WBO and The Ring magazine junior-flyweight titles between 2011 and 2016; IBF flyweight title from 2017 to 2018; and the WBO junior-bantamweight title from 2018 to 2019. He is the longest-reigning Filipino boxing world champion, surpassing in 2014 the record set in 1967 by Boxing Hall of Fame inductee Gabriel "Flash" Elorde. He was one of the first three Asian fighters with world titles in at least four weight classes alongside fellow Filipinos Manny Pacquiao and Nonito Donaire.
Arthur Anthony Johnson is a former professional boxer from the United States, nicknamed "Flash".
Joseph William Calzaghe is a Welsh former professional boxing world champion who competed from 1993 to 2008. He held world championships in two weight classes, including the unified WBA (Undisputed), WBC, IBF, WBO, Ring magazine and lineal super-middleweight titles, and the Ring light-heavyweight title.
Daniel Jiménez Román is a former Puerto Rican professional boxer. He is best known for having won the WBO title as a pro.
Lee Haskins is a British former professional boxer who competed between 2003 and February 2020. He held the IBF bantamweight title from 2015 to 2017, and the IBF interim title in 2015. At regional level, he held the Commonwealth flyweight title in 2006; the British super-flyweight title from 2008 to 2009; the Commonwealth super-flyweight title in 2009; the British bantamweight title in 2013; and the European bantamweight title twice between 2012 and 2015.
John Riel Reponte Casimero is a Filipino professional boxer and YouTuber. He has held world championships in three weight classes; including the IBF junior-flyweight title from 2012 to 2013; the IBF flyweight title in 2016; and the WBO bantamweight title from 2019 to 2022. Quadro Alas is Tagalog for four of a kind when translated, his moniker means Four Aces.
Paul Butler is an English professional boxer and two-time bantamweight world champion, having held the IBF title in 2014 and the WBO title in 2022. He also held multiple regional titles, including the British and Commonwealth super-flyweight titles in 2012 and 2013, respectively.
Zolani Tete is a South African professional boxer. He is a former two-weight world champion, having held the IBF junior-bantamweight title from 2014 to 2015 and the WBO bantamweight title from 2017 to 2019.
Joseph Kelly is a Scottish former boxer who won the ABA title and the Commonwealth Games silver medal at flyweight in 1982, and after turning professional was British bantamweight champion in 1992.
Jerwin Juntilla Ancajas is a Filipino professional boxer. He held the IBF junior-bantamweight title from 2016 to 2022.
Salvatore Fanni is an Italian former professional boxer who competed from 1988 to 2003. He held the European flyweight title from February 1991 to November 1992, and unsuccessfully challenged for the WBO flyweight title twice, as well as the WBO light flyweight title once.
Jonas Sultan is a Filipino professional boxer. He is the current WBO Inter-continental bantamweight champion. He held the IBF Inter-continental junior bantamweight title since December 2016 by beating South Africa's Makazole Tete.
Daniel Jiménez 
Welsh Institute of Sport, Cardiff, Wales
Ferid Ben Jeddou
Alberto Jiménez 
Luigi Camputaro
Mauricio Bernal
Adrian Cristian Ochoa