The 2004–05 season was the 105th season in Società Sportiva Lazio's history and their 17th consecutive season in the top-flight of Italian football.

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.