This is the list of all K-1 champions. Included are the K-1 World Grand Prix and K-1 World MAX champions as well as all the preliminary tournament winners from the events promoted by FEG (1993– 2011), K-1 Global (2012–2023), and K-1 (2014–present), following the former's dissolution. The list does not contain K-1's mixed martial arts branch Hero's and DREAM champions.

K-1 Championship

K-1 Super Heavyweight Championship

K-1 Heavyweight Championship

K-1 Cruiserweight Championship

K-1 Middleweight Championship

K-1 Super Welterweight Championship

K-1 Welterweight Championship

K-1 Super Lightweight Championship

K-1 Lightweight Championship

K-1 Super Featherweight Championship

K-1 Featherweight Championship

K-1 Super Bantamweight Championship

K-1 Bantamweight Championship

K-1 Women's Flyweight Championship

K-1 WORLD GRAND PRIX Champions

Openweight

K-1 and FEG (1993-2010), K-1 (2024–present)

K-1 WORLD GRAND PRIX : Finalists

K-1 and FEG (1993-2010), K-1 (2024–present)

K-1 GP Preliminary Tournament Champions

Legend:

K-1 WORLD MAX Champions

-70kg

K-1 and FEG (2002-2010), K-1 (2024–present)

K-1 WORLD MAX : Finalists

K-1 and FEG (2002-2010), K-1 (2024–present)

K-1 MAX Preliminary Tournament Champions

Legend:

K-1 World Tournament Champions

K-1 WORLD GP JAPAN (2014-2023), K-1 WORLD MAX (2024-present)

K-1 Japan Tournament Champions

K-1 Global Champions

Openweight -95 kg -85 kg -85 kg : Light Heavyweight -70 kg

K-2 / K-3 : Grand Prix Champions

K-2

Weight limit: 82 kg

K-3

Weight limit: 75 kg

K-1 Japan Amateur Champions

K-1 Japan Koshien Tournament Champions