Career
Couillard reached his career-high Association of Tennis Professionals Tour singles ranking of World Number. 569 in October 2002. He primarily plays on the Futures circuit and the Challenger circuit. In 2013, Couillard and Benjamin Balleret played the longest professional tiebreak in known tennis history, lasting 70 points (34–36).
Couillard lost the match 6–7(34), 1–6 in the third qualifying round for the United States of America F1 Futures in Plantation, Florida.