Born in 1990 in La Roche-sur-Yon, Sébastien Simon grew up in the Vendée and discovered sailing as a child aboard his father's boat. A structural and composites engineer, he started in the 420 dinghy and took third at the 2013 world championship.
In late 2013 he won the Challenge Espoir Bretagne-CMB and joined the Figaro circuit. He won the Solitaire du Figaro in 2018, along with the French Elite solo offshore title.
He then got a brand-new IMOCA, Arkéa-Paprec, and started the 2020-2021 Vendée Globe. After hitting a floating object that damaged his starboard foil, he retired in early December 2020.
Aboard Groupe Dubreuil he sailed the 2024-2025 Vendée Globe and finished third in 67 days 12 h 25 min 37 s despite a starboard foil failure in the southern Pacific; like the top two, he beat the previous race record.