Joseph Horatio Anderson was a British-born Colonial American architect active in Annapolis, Province of Maryland, in the late 18th century. He designed Whitehall (1764), a plantation house in Anne Arundel County, outside Annapolis. He was the likely designer of the third (and current) Maryland State House (1772). He designed the second St. Anne's Church (designed 1775, completed 1792), also in Annapolis, although the church was not completed until more than a decade after his death. Quite few details are known of Anderson's life.