The 1940 Lancashire Cup was the thirty-second occasion on which the Lancashire Cup completion had been held. Due to the start of the Second World War, there was no Lancashire Cup completion during 1939. The competition was delayed until early 1940. Swinton won the trophy by beating Widnes on a two legged final by the score of 21-15 aggregate. The first leg was played at Naughton Park, Widnes, and the second led was played at Station Road, Swinton. Swinton won both legs, 5-4 away and 16-11 at home. The attendances were 5,500 at Widnes and 9,000 at Swinton.