Konstantinos "Kostas" Fortounis (Greek: Κωνσταντίνος "Κώστας" Φορτούνης, pronounced ; (born 16 October 1992) is a Greek footballer who plays for Olympiacos and the Greece national team. He was born in Trikala, Thessaly but comes from the nearby town of Kalabaka.
After leaving Olympiacos' youth team in 2008, Fortounis moved to Trikala to play for AO Trikala. After an impressive spell in the Under-21 side scoring four goals in 14 matches, he began his career with the first team in the fourth division, where from 2008–2010 he played in 30 matches and scored 26 goals.
Because of his good appearances with the Greece under-17 national team, Vangelis Vlachos, Asteras Tripolis' manager convinced him to join the Peloponeesean team. He made his debut in a draw with PAOK in Tripolis. Used predominantly as a substitute, the teenager clocked up 24 league appearances, scoring his first Super League goal on 19 September 2010 in a 2–2 draw at AEK Athens, unable, however, to save the side from relegation. Due to his good performances at Asteras, Juventus made an offer in the winter transfer window for a loan transfer until summer with an option to buy him. Asteras finally declined Juventus's offer.