Erstwhile Susan is a 1919 American silent drama film directed by John S. Robertson, produced and distributed by Realart Pictures.

It is based on a 1914 novel Barnabetta by Helen Reimensnyder Martin and later Broadway play Erstwhile Susan by Marian De Forest.

As described in an adoption in the November 1919 issue of the film magazine Shadowland,[4] Barnabetta (Constance Binney) dreams of furthering her education, but her Mennonite father Jacob (Bradley Barker) disapproves.

Jacob later marries Erstwhile Susan (Mary Alden), who has money and changes the family relationships, and sends Barnabetta to college.

After graduation, she helps David Jordan (Jere Austin) run for the Senate, who then professes his love for her.