List of boxing quadruple champions

There is some dispute on which sanctioning body is considered "major" enough to award championships. The "Big 4" sanctioning bodies are always included. They are arranged in order of foundation:

• World Boxing Association (WBA) - founded in 1921
• World Boxing Council (WBC) - founded in 1963
• International Boxing Federation (IBF) - founded in 1976
• World Boxing Organization (WBO) - founded in 1988

The Ring, boxing's most respected magazine, has awarded world championships in professional boxing within each weight class from its foundation in 1922 until the 1990s, and again since 2001. The Ring champions were at one point held the linear reign to the throne, the man who beat the man. The lineal champion is also known as the true champion of the division. The Ring stopped giving belts to world champions in the 1990s but began again in 2002.

In 2002, The Ring attempted to clear up the confusion regarding world champions by creating a championship policy. It echoed many critics' arguments that the sanctioning bodies in charge of boxing championships had undermined the sport by pitting undeserving contenders against undeserving "champions", and forcing the boxing public to see mismatches for so-called "world championships". The Ring attempted to clear up the confusion regarding world champions by creating a championship policy that is "intended to reward fighters who, by satisfying rigid criteria, can justify a claim as the true and only world champion in a given weight class." The Ring claims to be more authoritative and open than the sanctioning bodies' rankings, with a page devoted to full explanations for ranking changes. A fighter pays no sanctioning fees to defend or fight for the title at stake, contrary to practices of the sanctioning bodies. Furthermore, a fighter cannot be stripped of the title unless he loses, decides to move to a different weight division, or retires.

There are currently only two ways that a boxer can win The Ring's title: defeat the reigning champion; or win a box-off between the magazine's number-one and number-two rated contenders (or, sometimes, number-one and number-three rated). A vacant Ring championship is filled when the number-one contender in a weight-division battles the number-two contender or the number-three contender (in cases where The Ring determines that the number-two and number-three contenders are close in abilities and records).

In May 2012, citing the number of vacancies in various weight classes as primary motivation, The Ring unveiled a new championship policy. Under the new policy, The Ring title can be awarded when the No. 1 and No. 2 fighters face one another or when the Nos. 1 and 2 contenders choose not to fight one another and either of them fights No. 3, No. 4 or No. 5, the winner may be awarded The Ring belt. In addition, there are now six ways for a fighter to lose his title: lose a fight in his championship weight class; move to another weight class; not schedule a fight in any weight class for 18 months; not schedule a fight in his championship weight class for 18 months, even if fighting at another weight class; not scheduling a fight with a top 5 contender in any weight class for two years; or retiring.

Many media outlets and members are extremely critical of the new championship policy and state that if this new policy is followed The Ring title will lose the credibility it once held.

The Transnational Boxing Rankings Board (TBRB) hands out the official version of the lineal championship. TBRB awards vacant championships when the two top-ranked fighters in any division meet and currently recognizes legitimate world champions or "true champions" each weight classes. The Board was formed to continue where The Ring "left off" in the aftermath of its purchase by Golden Boy Promotions in 2007 and the following dismissal of Nigel Collins. After the new editors announced a controversial new championship policy in May 2012, three prominent members of the Ring Advisory Panel resigned. This three members (Springs Toledo, Cliff Rold and Tim Starks) became the founding members of the Transnational Boxing Rankings Board, which was formed over the summer of 2012 with the assistance of Stewart Howe of England.

Since 2012, lineal champions are predetermined by the Transnational Boxing Rankings Board, which promotes the concept of a singular world champion per weight class.[1] Lineal champions are listed on Cyber Boxing Zone website which list lineal champions of the Queensberry Era to date.[2]

They are: International Boxing Organization (IBO), World Professional Boxing Federation (WPBF), International Boxing Association (IBA), International Boxing Council (IBC), International Boxing Board (IBB), International Boxing League (IBL), International Boxing Union (IBU), Global Boxing Association (GBA), Global Boxing Council (GBC), Global Boxing Federation GBF, Global Boxing Organization (GBO), Global Boxing Union (GBU), National Boxing Association (NBA), Transcontinental World Boxing Association (TWBA), Universal Boxing Association (UBA), Universal Boxing Council (UBC), Universal Boxing Federation (UBF), Universal Boxing Organization (UBO), UNIBOX, United States Boxing Council (USBC), World Athletic Association (WAA), World Boxing Board (WBB), World Boxing Championship Committee (WBCC), World Boxing Foundation (WBFo), World Boxing Institute (WBI), World Boxing League (WBL), World Boxing Network (WBN), World Boxing Union (WBU).

Note:

• The International Boxing Association (IBA) is not to be confused with the International Boxing Association (AIBA), a French acronym for Association Internationale de Boxe Amateur, which sanctions amateur matches.
• The National Boxing Association (NBA) was established in 1984 and is not to be confused with the original National Boxing Association that was established in 1921 and changed its name to World Boxing Association (WBA) in 1962.

• Dates in bold format signify the date when they won their 4th division title.
• Interim titles are not included unless they get promoted to the official champion.
• Only primary WBA champions are listed. Here are the scenarios:
  • Miguel Cotto's and Adrien Broner's WBA Regular welterweight title is considered the "primary title" because all possible primary champions were vacant at the time of their title reign.
  • Kazuto Ioka's WBA Regular light flyweight title is considered the "primary title" because Roman Gonzalez's WBA Super title was vacated one month before[32] Ioka relinquished his Regular title.[33] No bouts for the vacant WBA Super title were scheduled during that one month span thus legitimizing Ioka as WBA's "primary champion" for their light flyweight division.
  • Kazuto Ioka's WBA Regular flyweight title is considered the "primary title" because Juan Estrada's WBA Super title was vacated 2 years before[34] Ioka vacated his title.[35]Since Super's vacancy, Ioka defended his Regular title 2 more times. No bouts for the vacant WBA Super title were scheduled during that span of time thus legitimizing Ioka as WBA's "primary champion" for their flyweight division.
  • Canelo Álvarez's light middleweight Unified title is not listed because the primary champion at that time was Super champion Floyd Mayweather Jr. They later fought and Álvarez lost.
  • Canelo Álvarez's super middleweight Regular title is not listed because the primary champion at that time was Super champion Callum Smith. They later fought and Álvarez won the Super title.
• Any WBA titles won before the titles are fragmented in the division are not marked as Super, Undisputed, Unified, or Regular.

• Dates in bold format signify the date when they won their 4th division title.
• Interim titles are not included unless they get promoted to the official champion.

• Dates in bold format signify the date when they won their 4th division title.