John Henry Devereux (26 July 1840 – 16 March 1920), also called John Delorey before 1860, was an American architect and builder best known for his designs in Charleston, South Carolina. According to the National Park Service, he was the "most prolific architect of the post-Civil War era" in the Charleston area. His works are listed on the U.S. National Register of Historic Places. His Charleston Post Office and Courthouse has been designated as a U.S. National Historic Landmark.