Brian Todd O'Leary is an American scientist and a former NASA astronaut. He was one of the sixth group of astronauts selected by NASA in August 1967. This group of eleven were known as the scientist-astronauts, intended to train for the Apollo Applications Programa follow-on to the moon landings.
O'Leary is now retired and living in Ecuador. He is now a supporter of the free energy suppression theory and has written several books about it.