So Long Letty is a 1920 silent American comedy film directed by Al Christie and starring Grace Darmond, T. Roy Barnes, and Colleen Moore.

[2] Harry Miller (Barnes) is a party boy who loves the cabaret scene and nights on the town while his wife Grace is a homebody, distressed by her husband's errant ways.

Harry and Tommy hatch a plan to solve their problems; that they divorce their wives and swap.

They suggest a week-long trial period of platonic marriage, during which the wives do all they can to make their new potential mates miserable.

The Christie Film Company purchased the rights to the play So Long Letty from Oliver Morosco for $40,000 (equivalent to $608,372 in 2023).