Joseph Peter Kerwin is an American physician and former NASA astronaut. He served as the science pilot for the Skylab 2 mission from May 25, 1973, to June 22, 1973. He was the first physician to be selected for astronaut training and the first doctor from the United States to enter space.

Skylab 2 was the first crewed mission to Skylab, the first American orbital space station. The mission was launched on an Apollo command and service module by a Saturn IB rocket on May 25, 1973, and carried NASA astronauts Pete Conrad, Joseph P. Kerwin, Paul J. Weitz to the station. The name Skylab 2 also refers to the vehicle used for that mission. The Skylab 2 mission established a twenty-eight-day record for human spaceflight duration. Furthermore, its crew was the first space station occupants ever to return safely to Earth – the only previous space station occupants, the crew of the 1971 Soyuz 11 mission that had crewed the Salyut 1 station for twenty-four days, died upon reentry due to unexpected cabin depressurization.