| 1939–40 Welsh Cup | |
| Country: | Wales |
| Second: | Swansea Town |
| Prev Season: | 1938–39 |
| Next Season: | 1946–47 |
The 1939–40 FAW Welsh Cup is the 59th season of the annual knockout tournament for competitive football teams in Wales.
League name pointed after clubs name.
Eight winners from the Third round plus 18 new clubs.
| width=50 | Tie no | width=250 | Home | width=50 | Score | width=250 | Away |
|---|---|---|---|---|---|---|---|
| 1 | Chester (FL D3N) | 4–2 | Shrewsbury Town |
Ten winners from the Fourth round. Cardiff City, Chester and Southport get a bye to the Sixth round.
Five winners from the Fifth round plus Cardiff City, Chester and Southport.
| width=50 | Tie no | width=250 | Home | width=50 | Score | width=250 | Away |
|---|---|---|---|---|---|---|---|
| 1 | Chester (FL D3N) | 1–3 | Wellington Town (B&DL) | ||||
| 2 | New Brighton (FL D3N) | 1–0 | Southport (FL D3N) | ||||
| 3 | Cardiff City (FL D3S) | 1–1 | Newport County (FL D2) | ||||
| 4 | Swansea Town (FL D2) | 2–0 | Aberystwyth Town (MWL) | ||||
| Replay | Newport County (FL D2) | 5–0 | Cardiff City (FL D3S) |
Replay between Wellington Town and New Brighton were held at Shrewsbury.
| width=50 | Tie no | width=250 | Home | width=50 | Score | width=250 | Away |
|---|---|---|---|---|---|---|---|
| 1 | Swansea Town (FL D2) | 1–0 | Newport County (FL D2) | ||||
| 2 | Wellington Town (B&DL) | 0–0 | New Brighton (FL D3N) | ||||
| replay | Wellington Town (B&DL) | 4–2 | New Brighton (FL D3N) |
Final were held at Shrewsbury.
| width=50 | Tie no | width=250 | Home | width=50 | Score | width=250 | Away |
|---|---|---|---|---|---|---|---|
| 1 | Wellington Town (B&DL) | 4–0 | Swansea Town (FL D2) |