Stephen Decatur, Sr. (June 1751 – November 11, 1808) was an American naval captain in the Revolutionary War and later in the Quasi-War. He was the father of Stephen Decatur, Jr.
Born in Newport, Rhode Island, Decatur was a merchant captain before the Revolution. He married Ann Pine; in addition to their famous son, they had two other children, Lieutenant James Decatur, who was killed in action in 1804 during the Barbary Wars, and Ann Decatur McKnight.
During the American Revolution he commanded the Royal Louis, the Comet, the Retaliation, the Rising Sun, and the Fair American.
With the outbreak of the Quasi War with France, Decatur was commissioned as a captain in the United States Navy on May 11, 1798.
He commanded the ship USS Delaware and sailed in the first American Navy fleet to cross the Atlantic along with his son Stephen Decatur Jr.
In 1800, Decatur commissioned Philadelphia, the very vessel that his son later burned several months after it ran aground and was captured near Tripoli harbor in 1803.
In accordance with the Peace Establishment Act of 1801, which greatly reduced the United States Army and Navy, Decatur was discharged from the Navy on October 22, 1801.