All of a Sudden Peggy is a lost[1] 1920 American silent comedy romance film directed by Walter Edwards and starring Marguerite Clark and Jack Mulhall.

It is based on a 1907 Broadway play All-of-a-Sudden Peggy which starred Henrietta Crosman.

The sister of the peer sends for her son Jimmy (Mulhall) because she thinks Peggy has designs on Lord Anthony.

She goes to London where her pocket is picked, and has to stay at Jimmy's bachelor quarters while he is away on business.

The sudden appearance of Jimmy, his mother and father, and a prying neighbor precipitates matters, with Peggy having spent the night there suggesting a scandal.