Theodoros "Thodoris" Vlachos (Greek: Θοδωρής Βλάχος; born 9 July 1969, in Volos) is a retired Greek water polo player and the current coach of the Greece men's national water polo team. As a player, Vlachos played for Olympiacos from 1989 to 1998, winning numerous titles. He was also a member of the Greece men's national water polo team. After his retirement, he became assistant coach of Olympiacos under coaches Dragan Matutinović, Zoltán Kásás and Veselin Đuho. He became Olympiacos head coach in 2011, following a successful stint as head coach in Palaio Faliro. Under his guidance, Olympiacos won the 2017–18 LEN Champions League in Genoa, after a 9–7 win against home team Pro Recco in the final and completed a Triple Crown, winning the season's all available titles. Besides the LEN Champio