Born in the region, Fantin began skiing at the age of 2. Along with his father (ex-professional freestyle skier) and his brothers, he builds ski jumps in the snow. In parallel, he learnt the basics of acrobatics at a circus school. This is where he did his first backflips at the age of 8, and double backflips at 11.

Fantin was spotted by Ski Romand. In 2006, he gained two U15 Swiss champion titles and joined Swiss Ski.
During the 2019 season, he joined the Swiss team (team B / challenger team) thanks to the consistency of his results, particularly in the European Cup.

He resided at the National Performance Centre in Engelberg in order to combine sport and study.
Fantin Ciompi was born and lives in Antagnes. He went to school in Ollon and skied in Villars a great deal during his childhood.