The World Boxing Organization (WBO) is an organization which sanctions professional boxing bouts. It is recognized by the International Boxing Hall of Fame (IBHOF) as one of the four major world championship groups, alongside the World Boxing Association (WBA), World Boxing Council (WBC), and International Boxing Federation (IBF). The WBO's headquarters are located in San Juan, Puerto Rico.
Jorge Adolfo Páez is a Mexican actor, circus performer and former professional boxer. In boxing he held the WBO and IBF featherweight titles. Paez's nickname of "El Maromero" is in honor of the somersault acts he performs at the circus. It was in the circus that he learned acrobatic moves he would later use in the boxing ring. Páez is also the father of Azriel Páez, Jorge Páez Jr., and Airam Páez.
In boxing, the undisputed champion of a weight class is the boxer who simultaneously holds world titles from all recognized major organisations by each other and the International Boxing Hall of Fame. There are currently four major sanctioning bodies: WBA, WBC, IBF and WBO. There were many undisputed champions before the number of major sanctioning bodies recognizing each other increased to four in 2007, but there have only been 18 boxers to hold all four titles simultaneously.
As in the 1980s, the 1990s in boxing's popularity focused on all divisions. When 1980s legends Sugar Ray Leonard, Thomas Hearns, as well as others retired, newer superstars filled the void: Pernell Whitaker, Julio César Chávez, in the early 1990s, Oscar De La Hoya, Félix Trinidad, Roy Jones Jr. and Floyd Mayweather Jr. in the mid to late 1990s.
Katie Taylor is an Irish professional boxer and former footballer. She is the undisputed and lineal world lightweight champion since 2019, and the undisputed and lineal world super lightweight champion since 2023.
Julius Munyelele Indongo is a Namibian professional boxer. He is a former unified light-welterweight world champion, having held the WBA (Unified), IBF, and IBO titles between 2016 and 2017. As an amateur, Indongo represented Namibia at the 2008 Olympics, reaching the first round of the lightweight bracket.
Amanda Serrano is a Puerto Rican professional boxer, mixed martial artist and professional wrestler. As a boxer, she is the unified featherweight world champion, having held the WBO title since 2019, IBO title since 2021, IBF title since 2022 and the WBA title since 2023. She is the only female, and Puerto Rican, to win world titles in more than four weight classes, and holds the Guinness World Record for the most boxing world championships won in different weight-classes by a female, having held 9 major world titles across seven different weight classes.
Delfine Persoon is a Belgian professional boxer. She held the IBF female lightweight title in 2012 and the WBC female lightweight title from 2014 to June 2019, losing the title in a unification fight against Katie Taylor for the undisputed lightweight championship. As of September 2020, she is ranked as the world's best active female super-featherweight by BoxRec, the second best active female lightweight by The Ring, and the second best active female, pound for pound, by BoxRec, fifth by The Ring and seventh by ESPN.
Jessica McCaskill is an American professional boxer. She is a world champion in two weight classes, having held the undisputed, IBO, and Ring female welterweight titles since 2020; the WBC female super lightweight title from 2018 to 2020; and the WBA female super lightweight title from 2019 to 2020. She also challenged for the WBA lightweight title in 2017. As of September 2020, she is ranked as the world's best active female welterweight by The Ring and BoxRec, and the third best active female, pound for pound, by BoxRec, and fourth by The Ring and ESPN.
Chantelle Cameron is an English professional boxer. She is a former world champion in two weight classes, including the former undisputed light-welterweight champion, having held the WBC title between 2020 and 2023; the IBF and Ring magazine titles between 2021 and 2023 ; and the WBA and WBO titles between November 2022 and 2023. She previously held the IBO female lightweight title from 2017 to 2019 and light-welterweight title from 2022 to 2023.
Viviane Obenauf is a Brazilian former professional boxer who competed from 2014 to 2019. She has challenged three times for world titles; the IBO female lightweight title in 2017; the IBF female super featherweight title in 2018; and the IBO female super featherweight title in 2019.
Anisha Dzombe Basheel is a Malawian professional boxer who has held the Commonwealth female lightweight title since 2018 and the ABU female super-featherweight title since 2017.
Anahí Ester Sánchez is an Argentine professional boxer. She is a three-weight world champion, having held the IBF female super-featherweight title in 2016; the WBA female lightweight title in 2017; and the WBA female super lightweight title in 2019. She also held the WBA interim female featherweight title in 2015 and the WBA interim female super-lightweight title from 2018 to 2019, and challenged for the WBC and IBF female super-featherweight, and WBC female super-lightweight titles between 2016 and 2019.
Cindy Serrano is a Puerto Rican professional boxer who held the WBO female featherweight title from 2016 to 2017. She also challenged for the WIBA featherweight title in 2005; the WIBA and WIBF welterweight titles in 2011; and the unified WBA and IBF female lightweight titles in 2018. Her younger sister, Amanda, is also a professional boxer. The pair became the first sisters to hold world titles from major sanctioning bodies at the same time after Cindy captured the WBO title in 2016.
Jermell Charlo vs. Brian Castaño was a unification professional boxing match contested between WBA (Super), WBC, IBF, and The Ring light middleweight champion, Jermell Charlo, and WBO light middleweight champion, Brian Castaño, with the winner set to become the first undisputed light middleweight champion since Winky Wright in 2004 and the first in the four-belt era. The bout took place on July 17, 2021 that ended in a split draw.
Alycia Baumgardner is an American professional boxer. She has held the WBC and IBO female super featherweight titles since 2021, and the WBO, IBF, and The Ring female super featherweight titles since 2022. She became the undisputed female super featherweight champion of the world on February 4, 2023.
Katie Taylor vs. Amanda Serrano, billed as For History, was a women's lightweight professional boxing match contested between the undisputed world champion Katie Taylor and seven-division world champion Amanda Serrano. The bout was held on April 30, 2022, at Madison Square Garden in New York City, with Taylor's undisputed lightweight titles on the line. It was the first women's boxing match to headline Madison Square Garden, and was described as the 'biggest women's fight of all time'. Taylor defeated Serrano by split decision.
Halanna Dos Santos
Katie Taylor 
Liacouras Center, Philadelphia, Pennsylvania, U.S.
Yolis Marrugo Franco
Lourdes Borbua
Brenda Karen Carabajal
Yelka Torres