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)
WBA: Oleksandr Usyk*
WBC: Oleksandr Usyk**
IBF: Oleksandr Usyk
WBO: Fabio Wardley
*Murat Gassiev is the WBA "regular" champion
**Agit Kabayel is the WBC interim champion
Cruiserweight (200 lbs.)
WBA: Gilberto Ramirez
WBC: Norair Mikaeljan
IBF: Jai Opetaia
WBO: Gilberto Ramirez
Light heavyweight (175 lbs.)
WBA: Dmitry Bivol*
WBC: David Benavidez
IBF: Dmitry Bivol
WBO: Dmitry Bivol**
*David Benavidez is the WBA "regular" champion, and Albert Ramirez is the WBA interim champion
**Callum Smith is the WBO interim champion
Super middleweight (168 lbs.)
WBA: Jose Armando Resendiz
WBC: Christian Mbilli*
IBF: Vacant
WBO: Vacant
*Lester Martinez is the WBC interim champion
Middleweight (160 lbs.)
WBA: Erislandy Lara
WBC: Carlos Adames*
IBF: Vacant
WBO: Janibek Alimkhanuly
*Jesus Ramos is the WBC interim champion
Junior middleweight (154 lbs.)
WBA: Xander Zayas*
WBC: Sebastian Fundora**
IBF: Josh Kelly
WBO: Xander Zayas
*Jaron Ennis is the WBA interim champion
**Vergil Ortiz Jr. is the WBC interim champion
Welterweight (147 lbs.)
WBA: Rolando Romero
WBC: Ryan Garcia
IBF: Lewis Crocker
WBO: Devin Haney
Junior welterweight (140 lbs.)
WBA: Gary Antuanne Russell
WBC: Dalton Smith*
IBF: Richardson Hitchins
WBO: Shakur Stevenson
*Isaac Cruz is the WBC interim champion
Lightweight (135 lbs.)
WBA: Vacant*
WBC: Vacant**
IBF: Raymond Muratalla
WBO: Abdullah Mason
*Gervonta Davis is the WBA champion in recess.
**Jadier Herrera is the WBC interim champion
Junior lightweight (130 lbs.)
WBA: Anthony Cacace*
WBC: O'Shaquie Foster
IBF: Emanuel Navarrete
WBO: Emanuel Navarrete
*Elnur Samedov is the WBA interim champion
Featherweight (126 lbs.)
WBA: Brandon Figueroa
WBC: Bruce Carrington*
IBF: Angelo Leo
WBO: Rafael Espinoza
*Rey Vargas is the WBC champion in recess
Junior featherweight (122 lbs.)
WBA: Naoya Inoue
WBC: Naoya Inoue
IBF: Naoya Inoue
WBO: Naoya Inoue
Bantamweight (118 lbs.)
WBA: Seiya Tsutsumi
WBC: Takuma Inoue
IBF: Jose Salas Reyes
WBO: Christian Medina
Junior bantamweight (115 lbs.)
WBA: Jesse Rodriguez*
WBC: Jesse Rodriguez
IBF: Willibaldo Garcia Perez
WBO: Jesse Rodriguez
*David Jimenez is the WBA interim champion
Flyweight (112 lbs.)
WBA: Ricardo Sandoval*
WBC: Ricardo Sandoval**
IBF: Masamichi Yabuki
WBO: Anthony Olascuaga
*Jonathan Gonzalez is the WBA interim champion
**Galal Yafai is the WBC interim champion
Junior flyweight (108 lbs.)
WBA: Rene Santiago
WBC: Shokichi Iwata
IBF: Thanongsak Simsri
WBO: Rene Santiago
Strawweight (105 lbs.)
WBA: Oscar Collazo
WBC: Melvin Jerusalem
IBF: Pedro Taduran
WBO: Oscar Collazo