Vassilis Spanoulis (Greek: Βασίλης Σπανούλης) (born August 7, 1982) is a Greek professional basketball player who plays for the Greek Basket League and Euroleague club Olympiacos Piraeus. A 6 ft 4 in (1.93 m) tall guard, Spanoulis first played for Gymnastikos S. Larissa and enjoyed a highly successful career start, winning the Greek Basket League's Best Young Player award in 2002. His skill-set earned him a transfer to Athens and Maroussi. Following an impressive 2004–05 season, during which he led Maroussi to the Greek Basket League Finals, and the Eurocup quarterfinals, he moved to Panathinaikos, where he became one of European basketball's major stars.

In the Euroleague 2005–06 season, Spanoulis entered the Euroleague in impressive fashion, earning his first All-Euroleague Team selection as a rookie in the competition. After a stint in the NBA with the Houston Rockets during the 2006–07 season, he returned to Panathinaikos and led them to a Euroleague title in 2009, being voted as a member of the All-Euroleague Second Team, and the Euroleague Final Four MVP. His transfer to Olympiacos, in the summer of 2010, marked a new step in Spanoulis' career. Within a young and rebuilding Olympiacos team that was not expected to certainly make it past the regular season, Spanoulis led a Euroleague title run in the 2011-12 season. His unexpected championship triumph gained him a fourth All-Euroleague selection, and a second Euroleague Final Four MVP award.