The 2017–18 Legia Warsaw season is the club's 101st season of existence, and their 81st in the top flight of Polish football.

Legia entered the 2017–18 season as the defending Ekstraklasa champions.

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

Legia Warsaw won 3–2 on aggregate.

Win Draw Loss Moulin 76' Legia Warsaw won 9–0 on aggregate.