St. Stephens is an unincorporated census-designated place in Washington County, Alabama, United States. As of the 2010 census, its population was 495. Located near the Tombigbee River in the southwestern part of the state and 67 miles north of Mobile, it is composed of two distinct sites: Old St. Stephens and New St. Stephens. The Old St. Stephens site lies directly on the river and is no longer inhabited. It was the territorial capital of the Alabama Territory. Now encompassed by the Old St. Stephens Historical Park, it is listed on the National Register of Historic Places.Changes in the territorial capital and transportation resulted in the Old St. Stephens site being bypassed by development. "New" St. Stephens developed two miles inland around a railway station, but adjacent to the old site. It is the location of the post office, Baptist and Methodist churches, and residences.