The 1930–31 FAW Welsh Cup is the 50th season of the annual knockout tournament for competitive football teams in Wales.
League name pointed after clubs name.
- B&DL - Birmingham & District League
- CCL - Cheshire County League
- FL D2 - Football League Second Division
- FL D3N - Football League Third Division North
- FL D3S - Football League Third Division South
- SFL - Southern Football League
- WLN - Welsh League North
- WLS - Welsh League South
||Cross Street Gwersyllt
Eight winners from the Fourth round and eight new clubs.
Match between Swansea Town and Wrexham were held at Chester.