Stephen Douglas Thorne (February 11, 1953 – May 24, 1986), (Lt Cmdr, USN), was an American naval officer and aviator, test pilot and a NASA astronaut candidate.

He graduated from T. L. Hanna High School, Anderson, South Carolina, in 1971 and received a Bachelor of Science degree in Systems Engineering from the United States Naval Academy in 1975.

He completed F-18 Hornet transition training in October 1984 and joined Strike Fighter Squadron 132 (VFA-132) aboard USS Coral Sea until departing for NASA.

Thorne was killed in an aircraft accident of a stunt plane, in which he was a passenger, on May 24, 1986, two months before his astronaut class graduated.

The stunt plane crashed while performing maneuvers near Santa Fe, Texas, killing Thorne and NASA engineer James Simons.