Thierry Lacroix (born 2 March 1967 in Nogaro, France) is a former French rugby union footballer. He won 43 caps playing at fly-half for the French rugby union side. He made his international test debut at the age of 22 on 4 November 1989 as a replacement against Australia. He was part of the winning side in the 1993 Five Nations Championship. He won his final cap the 22 November 1997 against South Africa. Lacroix played in the 1991 Rugby World Cup and again in the 1995 Rugby World Cup in which he was the top points scorer with 112 points.
Lacroix started his rugby career at US Dax in the French Ligue Nationale de Rugby. After the 1995 Rugby World Cup in South Africa, he joined Natal Sharks in South Africa where he helped them to two Currie Cups in 1995 and 1996. He then left South Africa for England where he played for Harlequin F.C. and Saracens F.C. In 2000 he left Saracens to join USA Perpignan in France just as Thomas Castaignède signed to take up a position. Lacroix, a qualified physiotherapist, wanted to work in this domain and only played part-time rugby for Perpignan. He finished his rugby playing career at Castres Olympique at the age of 37.