Gustavo Eddy Balart Marin[1] (born February 10, 1987) is a Cuban mixed martial artist competing in the Strawweight division of ONE Championship.

[2][3] Gustavo Balart defeated Venezuela's Jorge Cardozo for the gold medal in his division at the 2011 Pan American Games in Guadalajara, Mexico.

Gustavo Balart made his ONE Championship debut against Tatsumitsu Wada at ONE: Roots of Honor in the ONE Flyweight World Grand Prix Quarterfinal on April 12, 2019.

[11] Gustavo Balart was able to pick up his first promotional victory with a unanimous decision over Ryuto Sawada at ONE: Battleground on July 30, 2021.

[18] Balart faced Jarred Brooks for the interim ONE Strawweight World Championship on August 3, 2024, at ONE Fight Night 24.