1956–57 was the forty-fourth occasion on which the Lancashire Cup completion had been held.
Oldham won the trophy by beating St. Helens by the score of 10-3 The match was played at Central Park, Wigan, (historically in the county of Lancashire).
The excellent attendance was 39,544 and receipts were £6,274 This was the first of Oldham's three consecutive triumphs.
1958 would be the last time they would win the trophy, although they did later appear 4 times as runners-up (in 1966, 1969, 1987 and 1989 With the invitation to junior club “County Amateurs”, the number of clubs remained the same at 15.
The same pre-war fixture format was retained, and due to the number of clubs this resulted in one bye in the first round.