Stella Hemetsberger was born on January 28, 1999, in Vienna and grew up in Salzburg, Austria. She discovered Muay Thai more or less by chance at the age of thirteen and was immediately captivated by it. She built her foundation at RS-GYM Salzburg under trainers Roland Schwarz and Christin Fiedler, and became Austrian K-1 champion at an early age. Alongside her combat sports career, she studied mechanical engineering, reflecting the discipline and structured approach she also displays in the ring.
Her international breakthrough came through the amateur circuit: she won gold at the 2022 World Games in Birmingham, Alabama, and claimed the world title in the K-1 division at the 2023 WAKO World Championship. To further raise her level, she moved to Phuket Fight Club in Thailand, where she was, among other things, a training partner of ONE atomweight champion Allycia Hellen Rodrigues. That experience convinced her that a professional career at the highest level was within reach.
At ONE Championship, she built a string of convincing victories through ONE Friday Fights. In September 2025, her major breakthrough followed: at ONE Fight Night 35, she defeated established American-Filipino star Jackie Buntan by unanimous decision in a five-round thriller and claimed the vacant ONE Women’s Strawweight Muay Thai World Title. Five months later, in February 2026, she repeated the feat in kickboxing: in a rematch, she defeated Buntan again, this time by split decision, becoming the Women’s Strawweight Kickboxing World Champion as well. This made her the third woman in ONE Championship history, after Stamp Fairtex and Janet Todd, to simultaneously hold titles in two combat sports.
As of September 2026, Hemetsberger remains the reigning world champion in both disciplines. On August 14, 2026, she defended her Muay Thai title with a third-round knockout against Russia’s Natalia Diachkova at ONE Fight Night 46 in Bangkok. Despite her rapid rise, she remains grounded: she still describes herself as “the same person” who continues to work hard and even feels somewhat uncomfortable with her status as a star. She is trained by Roland Schwarz and Christin Fiedler at RS-GYM Salzburg, supplemented by training camps at Phuket Fight Club in Thailand.
Austria
