The 2005–06 RCD Espanyol season was RCD Espanyol's 12th consecutive season in top-division of the Spanish football league, the La Liga, and the 106th as a football club.
In the quarter-finals they beat FC Basel of Switzerland 4–3 on aggregate (after losing the first leg 2–0 and being 1–0 down in the second leg, they scored 4 goals), this put them into the semi-final to face Steaua București.