During the 2003–04 Turkish football season, Gençlerbirliği S.K. competed in the Süper Lig.
Season summary
Gençlerbirliği reached the fourth round of the UEFA Cup before being knocked out by eventual runners-up Valencia.
First-team squad
Squad at end of season
Note: Flags indicate national team as defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.
UEFA Cup
First round
Second round
Gençlerbirliği won 4–1 on aggregate.
Third round
Gençlerbirliği won 4–0 on aggregate.
Fourth round
Valencia won 2–1 on aggregate.
