1965–66 Welsh Cup

The 1965–66 FAW Welsh Cup is the 79th season of the annual knockout tournament for competitive football teams in Wales.

Key
League name pointed after clubs name.
 * CCL - Cheshire County League
 * FL D2 - Football League Second Division
 * FL D3 - Football League Third Division
 * FL D4 - Football League Fourth Division
 * SFL - Southern Football League
 * WLN - Welsh League North

Fifth round
Ten winners from the Fourth round and six new clubs.

Final
Replay were held at Chester.