Stephen A. Decatur (1815–1876) was a nephew of Commodore Stephen Decatur, Jr.. He was one of the incorporators of Decatur, Nebraska.
Born in New Jersey, he was the son of Captain John Pine Decatur, United States Army, and grandson of Stephen Decatur, Sr..
Decatur had arrived in the area of the town from Bellevue in the 1840s and made his home with the Omaha tribe. Later he was a clerk at Sarpy's trading post and lived on a farm which was called "Decatur Springs," owing to the pure spring found there.
The town of Decatur was incorporated in 1856 under the name "The Decatur Townsite & Ferry Company." The other incorporators included Thomas Whiteacre, T. H. Hineman, George Mason, and Herman Glass. The patents for the town were granted on May 1, 1862.