|Date of birth||24 March 1976|
|Place of birth||Volos, Greece|
|Height||1.79 m (5 ft 10 1⁄2 in)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 4 May 2014 (UTC).
Athanasios Kostoulas (Greek: Θανάσης Κωστούλας; born 24 March 1976) is a former Greek football player. A determined tackler with timing to match, Kostoulas preferred to operate as a defensive midfield player but has played in every position across the back line.
Kostoulas stayed for a year at his first professional club, Olympiacos Volou, before stepping up to Kalamata FC for the 1994/95 campaign. The highlight of his five seasons there, which reaped 135 league appearances, was the club's promotion to the Alpha Ethniki in 1995. In July 1999, he joined Olympiacos CFP and ended each of his first three terms with a Greek championship medal. He started the following season on the bench but when handed an opportunity he took it, playing in seven out of the final eight games and excelling in the derby defeat of Panathinaikos FC which paved the way for another championship success. He remained a consistent performer when used as the title was lost in 2003/04 and then won back in each of the next two seasons along with the Greek Cup.
Kostoulas was a member of the Greece side reached the 1998 UEFA European Under-21 Championship final, losing 1–0 to Spain. He was then elevated into the senior fold, making his debut in a 4–2 FIFA World Cup qualifying defeat by Germany on 28 March 2001 but has not figured again since a second cap a month later against Croatia.
- Superleague Greece (7): 1999–2000, 2000–01, 2001–02, 2002–03, 2004–05, 2005–06, 2006–07
- Greek Cup (2): 2004–05, 2005–06
- "Croatia 2–2 Greece, match report". Soccerway. 25 April 2001. Retrieved 21 April 2012.