St. Elmo is an unincorporated community in Mobile County, Alabama, United States.

Originally a farming community, the town was served by the L&N Railroad which provided passenger and freight depots.

The town derives its name from the book of the same name, authored by Augusta Evans Wilson.

An airfield located just north of Highway 90, west of town was an outlying field of Brookley Air Force Base in Mobile.

African American elementary students attended the Grand Bay Elementary School for Colored, located west of town near Grand Bay.