The 1965–66 season of the European Cup Winners' Cup club football tournament was won by Borussia Dortmund in an extra-time final victory over Liverpool at Hampden Park in Glasgow.

This season of the Cup Winners' Cup was the first instance of the away goals rule being applied in football history.

CSKA Cherveno Zname won 4–1 on aggregate.

West Ham United won 6–2 on aggregate.

4–4 on aggregate; Budapest Honvéd won on away goals.

West Ham United won 2–1 on aggregate.