With 17 weight classes in boxing and four major sanctioning bodies that bestow world titles, keeping track of who holds each of the belts can be difficult -- especially when there are sometimes multiple titlists in each organization because of interim and secondary belts.
To make it easier for boxing fans, below is a quick reference chart of who holds each of the titles in the four organizations
To check the top 10 fighters in each division, visit ESPN's divisional rankings.
For a list of the best fighters regardless of weight class, check ESPN's pound-for-pound rankings.
Heavyweight (Unlimited)
WBO: Anthony Joshua
IBF: Anthony Joshua
WBA: Anthony Joshua*
WBC: Tyson Fury**
*Trevor Bryan is the WBA "regular" heavyweight champion
**Dillian Whyte is the WBC interim heavyweight champion
Cruiserweight (200 lbs.)
WBO: Lawrence Okolie
IBF: Mairis Briedis
WBA: Arsen Goulamirian*
WBC: Ilunga Makabu
*Ryad Merhy is the WBA "regular" cruiserweight champion
Light heavyweight (175 lbs.)
WBO: Joe Smith Jr.
IBF: Artur Beterbiev
WBA: Dmitry Bivol*
WBC: Artur Beterbiev
*Jean Pascal is the WBA "regular" light heavyweight champion and Robin Krasniqi is the WBA interim light heavyweight champion
Super middleweight (168 lbs.)
WBO: Canelo Alvarez
IBF: Caleb Plant
WBA: Canelo Alvarez*
WBC: Canelo Alvarez
*David Morrell is the WBA "regular" super middleweight champion
Middleweight (160 lbs.)
WBO: Demetrius Andrade
IBF: Gennadiy Golovkin
WBA: Ryota Murata*
WBC: Jermall Charlo**
*Erislandy Lara is the WBA "regular" middleweight champion, and Chris Eubank Jr. is the WBA interim middleweight champion
**Canelo Alvarez is the WBC "franchise champion"
Junior middleweight (154 lbs.)
WBO: Brian Castano
IBF: Jermell Charlo
WBA: Jermell Charlo*
WBC: Jermell Charlo
*Erislandy Lara is the WBA "regular" junior middleweight champion
Welterweight (147 lbs.)
WBO: Terence Crawford
IBF: Errol Spence Jr.
WBA: Yordenis Ugas*
WBC: Errol Spence Jr.
*Jamal James is the WBA "regular" champion
Junior welterweight (140 lbs.)
WBO: Josh Taylor
IBF: Josh Taylor
WBA: Josh Taylor*
WBC: Josh Taylor
*Mario Barrios is the WBA "regular" junior welterweight champion and Alberto Puello is the WBA interim junior welterweight champion
Lightweight (135 lbs.)
WBO: Teofimo Lopez Jr.
IBF: Teofimo Lopez Jr.
WBA: Teofimo Lopez Jr.*
WBC: Devin Haney**
*Gervonta Davis is the WBA "regular" lightweight champion and Rolando Romero is the WBA interim lightweight champion
**Teofimo Lopez Jr. is the WBC "franchise" champion and Ryan Garcia is the WBC interim champion
Junior lightweight (130 lbs.)
WBO: Jamel Herring*
IBF: Vacant
WBA: Gervonta Davis**
WBC: Oscar Valdez
*Shakur Stevenson is the WBO interim junior lightweight champion
**Roger Gutierrez is the WBA "regular" junior lightweight champion and Chris Colbert is the WBA interim junior lightweight champion
Featherweight (126 lbs.)
WBO: Emanuel Navarrete
IBF: Vacant
WBA: Leo Santa Cruz*
WBC: Gary Russell Jr.
*Xu Can is the WBA "regular" featherweight champion, and Eduardo Ramirez is the WBA interim featherweight champion
Junior featherweight (122 lbs.)
WBO: Stephen Fulton
IBF: Murodjon Akhmadaliev
WBA: Murodjon Akhmadaliev*
WBC: Brandon Figueroa
*Brandon Figueroa is the WBA "regular" junior featherweight champion and Raeese Aleem is the WBA interim junior featherweight champion
Bantamweight (118 lbs.)
WBO: John Riel Casimero
IBF: Naoya Inoue
WBA: Naoya Inoue*
WBC: Nonito Donaire
*Guillermo Rigondeaux is the WBA "regular" bantamweight champion
Junior bantamweight (115 lbs.)
WBO: Kazuto Ioka
IBF: Jerwin Ancajas
WBA: Roman "Chocolatito" Gonzalez*
WBC: Juan Francisco Estrada
*Joshua Franco is the WBA "regular" junior bantamweight champion
Flyweight (112 lbs.)
WBO: Junto Nakatani
IBF: Sunny Edwards
WBA: Artem Dalakian*
WBC: Julio Cesar Martinez**
*Luis Concepcion is the WBA interim flyweight champion and McWilliams Arroyo is the WBC interim flyweight champion
Junior flyweight (108 lbs.)
WBO: Elwin Soto
IBF: Felix Alvarado
WBA: Hiroto Kyoguchi*
WBC: Kenshiro Teraji
*Carlos Canizales is the WBA "regular" junior flyweight champion and Daniel Matellon is the WBA interim junior flyweight champion
Strawweight (105 lbs.)
WBO: Wilfredo Mendez
IBF: Rene Mark Cuarto
WBA: Knockout CP Freshmart*
WBC: Panya Pradabsri
*Victorio Saludar is the WBA "regular" strawweight champion