The Magic Cup is a lost[1] 1921 American silent adventure film directed by John S. Robertson and written by E. Lloyd Sheldon.

[2] Every time Mary Mallory needs money she pawns a silver cup which her mother left to her.

The Patrician, a crook, tells Abe the pawn broker, that Mary must be the granddaughter of Lord Fitzroy, an Irish nobleman.

Bob, a reporter known to Mary in her dishwasher days, falls in love with her but is suspicious of her "relatives".

The man dies, Mary pleads for the freedom of the crooks and then goes back to Ireland with Bob and her real grandfather.