Freeman was born on February 18, 1930, in Haverford, Pennsylvania, and completed his secondary education in 1948. He attended the University of Delaware at Newark for one year, then entered the United States Naval Academy and graduated in 1953 with a Bachelor of Science degree. In 1960, he received a Master of Science degree in Aeronautical Engineering from the University of Michigan.  Freeman graduated from both the Air Force’s Experimental Test Pilot and Aerospace Research Pilot School courses. He elected to serve with the Air Force. His last Air Force assignment was as a flight test aeronautical engineer and experimental flight test instructor at the ARPS at Edwards Air Force Base in the Mojave Desert.

He served primarily in performance flight testing and stability testing areas. He logged more than 3,300 hours flying time, including more than 2,400 hours in jet aircraft. Freeman was one of the third group of astronauts selected by NASA in October 1963. He was assigned the responsibility of aiding the development of boosters.  On the morning of Saturday, October 31, 1964, Theodore Freeman was making a return flight from McDonnell-Douglas training facilities in St. Louis, MO. He was killed during final approach to landing at Ellington Air Force Base, Houston, Texas, when a goose flew into the port-side air intake of his NASA-modified T-38 Talon jet trainer causing immediate engine failure. The bird strike was plainly observed by two airmen on duty in the Ellington AFB Air Traffic Control Tower Cab. Flying shards of Plexiglas may have entered the jet engine during the crash. Within seconds of the goose strike, the plane pancaked short of the base perimeter fence onto a public highway and caused the plane to immediately and violently lose structural integrity. The two observers did not witness any evidence of Freeman ejecting from the stricken aircraft, but it was too close to the ground for a parachute to open properly in any event.

Freeman was survived by his wife Faith Clark Freeman and one daughter, Faith Huntington. Faith Freeman first heard of her husband’s death when a reporter came to her house: NASA subsequently ensured that in the case of future astronaut deaths, their families were informed by other astronauts as quickly as possible.