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.
O'Neil Bell was a Jamaican professional boxer who competed from 1998 to 2011. He held the undisputed cruiserweight title in 2006 and the lineal cruiserweight title from 2006 to 2007.
In professional boxing, the undisputed champion of a weight class is the boxer who simultaneously holds world titles from all sanctioning organisations recognized major 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.
Cecilia Carmen Linda Brækhus is a Norwegian professional boxer and former kickboxer. In boxing she reigned as the undisputed female welterweight champion from 2014 to 2020, and is the first woman in any weight class to hold the WBA, WBC, IBF and WBO titles simultaneously. She is also one of only 11 boxers in history, female or male, to hold all four major world titles simultaneously. In 2017, the Boxing Writers Association of America named Brækhus their inaugural Female Fighter of the Year. Guinness World Records awarded her with three recognitions in 2018: the Longest Reigning Female Boxing Champion, the Longest Reign as a Four-Belt Undisputed Boxing Champion, and the Most Bouts Undefeated by a Female World Champion Boxer. As of September 2020, she is ranked as the world's second best active female welterweight by The Ring and BoxRec, and the third best active female, pound-for-pound, by The Ring, fifth by ESPN, and sixth BoxRec.
The history of boxing in the Philippines is the history of boxing and the evolution and progress of the sport in the Philippines. In the Philippines, boxing is one of its most popular sports, together with basketball, due to the many accolades it has brought to the country, having produced 45 major world champions, one of the most in the world. Despite not having won a gold medal in boxing, the Philippines has had multiple Olympic standouts, with 8 out of its 12 total Olympic medals coming from boxing, along with some of the greatest fighters in the history of the sport. Filipino greats like Pancho Villa and Flash Elorde are members of the two highly respected boxing hall of fames – International Boxing Hall of Fame (IBHOF) and World Boxing Hall of Fame (WBHF) thus, giving the Philippines the most number of boxing hall of fame members out of Asia.
Josh Taylor is a Scottish professional boxer. He is a former undisputed super lightweight champion, having held the International Boxing Federation (IBF) and World Boxing Association (WBA) titles between 2019 and 2022, the World Boxing Council (WBC) title between 2021 and 2022, the World Boxing Organisation (WBO) title between 2021 and 2023 and the Ring magazine title between 2019 and 2023. At regional level, he held the Commonwealth light-welterweight title from 2016 to 2017. As an amateur, he won a lightweight silver medal at the 2010 Commonwealth Games and light-welterweight gold at the 2014 edition.
Naoya Inoue is a Japanese professional boxer. Nicknamed "The Monster", Inoue is known for his timing, speed, punching power, and body-punching ability, having a knockout ratio of 92%. He is a four-division world champion and the current unified super bantamweight world champion, holding both the WBC and WBO super bantamweight titles since July 2023. He is also the former undisputed bantamweight world champion, having held the WBA (Super), IBF, Ring magazine titles between 2019 and January 2023, and the WBC and WBO titles between 2022 and January 2023. He previously held the WBA (Regular) bantamweight title from 2018 to 2019, the WBO junior-bantamweight title from 2014 to 2018, and the WBC light-flyweight title in 2014.
Marlon Tapales is a Filipino professional boxer. He has held world championships in two weight classes, including the unified WBA (Super) and IBF super-bantamweight titles since April 2023 and previously the WBO bantamweight title from 2016 to 2017.
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.
Franchón Crews-Dezurn is an American professional boxer. She was the undisputed world champion at super middleweight, losing to Savannah Marshall on 2 July 2023. She held the World Boxing Council (WBC) titles between 2018 and 2023; the World Boxing Organization (WBO) title between 2019 and 2023; and the World Boxing Association (WBA) and International Boxing Federation (IBF) title between 2022 and 2023. As of May 2022, she is ranked as the world's best active female super middleweight by The Ring and BoxRec.
Terence Crawford vs. Julius Indongo was a professional boxing match contested for the undisputed light welterweight championship between undefeated WBC, WBO, and The Ring champion Terence Crawford, and undefeated WBA (Unified), and IBF champion Julius Indongo. The bout took place on August 19, 2017, at the Pinnacle Bank Arena in Lincoln, Nebraska. Crawford defeated Indongo via third-round KO.
José Ramírez vs. Josh Taylor, billed as Undisputed, was a unification professional boxing match contested between WBC and WBO champion, José Ramírez, and WBA (Super), IBF, and The Ring champion, Josh Taylor. The bout took place on May 22, 2021, at the Virgin Hotels in Paradise, Nevada. Taylor defeated Ramirez via unanimous decision to become the undisputed light welterweight champion.
Naoya Inoue vs. Paul Butler, billed as Undisputed, was a bantamweight unification professional boxing match contested between WBA (Super), WBC, IBF, and The Ring champion, Naoya Inoue, and WBO champion, Paul Butler. Inoue knocked out Butler and became the undisputed bantamweight champion and the first since Enrique Pinder beat Rafael Herrera in 1972. The bout took place on 13 December 2022, at Ariake Arena in Tokyo, Japan.
José Quirino 
Eidy Moya 
Manning Galloway 
Manny Siaca 
Markus Beyer 
Carl Froch 