Triathlon de Lorient is a city triathlon held in Lorient, Morbihan, on the Brittany coast, typically in early June. The primary adult competitions include a Sprint-distance S race (750 m swim, 25 km road bike, 5 km run) and an M-distance race (1,500 m swim, 40 km road bike, 10 km run). Both adult formats are open to solo participants or relay teams, with 280 spots allocated for each race.
The S bike course consists of three laps without drafting, followed by a two-lap run. The M race features a two-lap swim with an Australian exit, then a three-lap bike leg also without drafting, and concludes with a three-lap run. The event also offers a comprehensive children's program. The youngest participants compete in a short run-bike-run duathlon, while older age groups progress to 50 m, 100 m, and 200 m swims, followed by bike and run segments adjusted for their age. Minimum age requirements differentiate solo and relay entries, ensuring the event accommodates children, teenagers, novice adults, relay teams, and seasoned triathletes within the Lorient venue.