John Leonard "Jack" Swigert, Jr. (August 30, 1931 – December 27, 1982) was an American test pilot, mechanical engineer, aerospace engineer, United States Air Force pilot, and NASA astronaut, one of the 24 persons who have flown to the Moon. After leaving NASA, he was elected to Congress from Colorado's new 6th district, but died before being sworn in.
Swigert died in Washington, D.C. from respiratory failure caused by nose cancer, aged 51.