Mixed martial arts champions come in all sizes -- from heavyweights up to 265 pound, to atomweights at 105 pounds. They come from all around the world -- from Australia to Brazil to Clevelend to Dagestan. They fight for organizations ranging from the UFC, the biggest fight promotion in the world, to Bellator and the PFL, as well as Asian powerhouse ONE Championship and Japan's Rizin, and the all-women fight organization Invicta FC.
Here are the champions from all of those promotions, updated through Sept. 18.
Click here for a look at the current and all-time UFC champions.
To keep up with current fights, go to the MMA schedule page.
HEAVYWEIGHT (265 pounds and under)
UFC: Stipe Miocic
Bellator: Ryan Bader
ONE: Brandon Vera
PFL: Philipe Lins
LIGHT HEAVYWEIGHT (205)
UFC: Jon Jones
Bellator: Ryan Bader
ONE: Aung La Nsang
PFL: Sean O'Connell
Rizin: Jiri Prochazka
MIDDLEWEIGHT (185)
UFC: Israel Adesanya
Bellator: Rafael Lovato Jr.
ONE: Aung La Nsang
PFL: Louis Taylor
WELTERWEIGHT (170)
UFC: Kamaru Usman
Bellator: Douglas Lima
ONE: Zebaztian Kadestam
PFL: Magomed Magomedkerimov
LIGHTWEIGHT (155)
UFC: Khabib Nurmagomedov
Bellator: Patricio Freire
ONE: Christian Lee
PFL: Natan Schulte
MEN'S FEATHERWEIGHT (145)
UFC: Max Holloway
Bellator: Patricio Freire
ONE: Martin Nguyen
PFL: Lance Palmer
MEN'S BANTAMWEIGHT (135)
UFC: Henry Cejudo
Bellator: Vacant
ONE: Bibiano Fernandes
Rizin: Vacant
MEN'S FLYWEIGHT (125)
UFC: Henry Cejudo
ONE: Adriano Moraes
MEN'S STRAWWEIGHT (115)
ONE: Joshua Pacio
WOMEN'S FEATHERWEIGHT (145)
UFC: Amanda Nunes
Bellator: Julia Budd
Invicta: Felicia Spencer
WOMEN'S BANTAMWEIGHT (135)
UFC: Amanda Nunes
Invicta: Sarah Kaufman
WOMEN'S FLYWEIGHT (125)
UFC: Valentina Shevchenko
Bellator: Ilima-Lei Macfarlane
Invicta: Vanessa Porto
WOMEN'S STRAWWEIGHT (115)
UFC: Zhang Weili
ONE: Jingnan Xiong
Invicta: Brianna Van Buren
ATOMWEIGHT (105)
ONE: Angela Lee
Rizin: Ayaka Hamasaki
Invicta: Jinh Yu Frey