Up in Mabel's Room is a play written by Wilson Collison and Otto Hauerbach.

Garry Ainsworth is married to Geraldine, who is jealous of his previous relationship with a pretty young widow, Mabel Essington.

When they were together, Garry gave Mabel a chemise with their names embroidered on it.

The characters and cast from the Broadway production are given below: The play opened at the Eltinge 42nd Street Theatre on January 15, 1919.

A 1926 silent film adaptation starred Marie Prevost as Mabel.