The 2003–04 RCD Espanyol season was the club's 10th consecutive season in the top division of the Spanish football league, La Liga, and the 104th in the club's history.

Updated on 21 January 2024[2] Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Players may hold more than one non-FIFA nationality.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Players may hold more than one non-FIFA nationality.