Xavier Bastard (born 25 August 1984) is a French former professional Muay Thai fighter who also competed in Kickboxing and under K-1 rules. He is a former WPMF World and Intercontinental Lightweight champion.
Bastard began practicing Muay Thai at the age of 16 at AS Cobra, a French combat sports association, where he was trained by Fred Dejonghe.
Bastard began his professional career in the mid-2000s, primarily competing under traditional Muay Thai rules in France and internationally. Over the course of his career, he also took part in kickboxing and K-1 rules competitions.
In 2011, Bastard challenged Apisit Koedchatturat for the WPMF World Lightweight title, losing by unanimous decision. Later that year, he captured the WPMF Intercontinental Lightweight title. In January 2012, he won the WPMF World Lightweight title by unanimous decision against Rob Storey.
Bastard also competed internationally under K-1 rules, notably in Japan, where he participated in the Krush promotion. In 2013, he reached the finals of the Krush 29 tournament for the ISKA World Lightweight title, losing by technical knockout to Koya Urabe.
After a three-year absence from competition, Bastard returned to the ring in June 2018. He continued to compete until 2022, recording his final professional victory at United Fight Night in Brest, France.
From 2016 onward, Bastard combined his professional fighting career with coaching. He became a Muay Thai coach at Kaeng Studio Sport, a gym based in Vannes, France, where he teaches Muay Thai to amateur and competitive fighters.