Marianne Fatton (born 16 December 1995) is a Swiss ski mountaineer. She represented Switzerland at the 2026 Winter Olympics, and won a gold medal in the sprint race.
Fatton competed at the 2023 World Championship of Ski Mountaineering and won a silver medal in the sprint race with a time of 3:14.005.
In March 2025, she competed at the 2025 World Championship of Ski Mountaineering and won a gold medal in the sprint race, with a time of 3:20.96. With the win, she earned a quota spot for the discipline at the 2026 Winter Olympics. She also won a bronze medal in the mixed relay, along with Robin Bussard, with a time of 33:02.9.
On 19 February 2026, Fatton won the first-ever Olympic gold medal in ski mountaineering, finishing in first place in the sprint race with a time of 2:59.77. On 21 February 2026, she won a silver medal in the mixed relay, along with Jon Kistler, with a time of 27:09.30.
Fatton's mother, Anna Janouà ¡ková, is a former Olympic cross-country skier who competed at the 1992 Winter Olympics.