Leitner made his debut for Germany U21 in a 4–1 win over Cyprus U21 on 9 August 2011. Leitner scored his first Germany U21 goal on 10 October 2011 in an 8–0 win over San Marino U21. He captained the team three times. Leitner was also included in the UEFA European Under-21 Championship squad, playing once in the tournament.