William Frederick Fisher (born April 1, 1946) is an American physician and a former NASA astronaut.

His technical assignments included: scientific equipment operator for high altitude research on the WB-57F aircraft (1980–1981); astronaut medical support for the first four Shuttle missions (1980–1982); astronaut office representative for Extravehicular Mobility Unit (spacesuit) and Extravehicular Activity (EVA) procedures and development, including thermal vacuum testing of the suit (1981–1984); astronaut office representative for the Payload Assist Module (PAM-D) procedures and development (1982–1983); Astronaut office representative for Shuttle Mission Simulator (SMS) development (1983); support crewman for STS-8; CAPCOM for STS-8 and STS-9; Remote Manipulator System (RMS) hardware and software development team (1983); Manned Maneuvering Unit (MMU) development team (1983); Deputy Director of NASA Government-furnished and Contractor-furnished Equipment (1982–1983); Chief of Astronaut Public Appearances (1985–1987); Member of the U.S. Air Force Scientific Advisory Board (1986–1991); NASA Medicine Policy Board (1987–1991); Astronaut Office Space Station Manned Systems Division, and Health Maintenance Facility (1987–1989); Astronaut Office representative on space crew selection and retention standards for Space Station (1989–1991).

Fisher also continued to practice Emergency Medicine in the greater Houston area in conjunction with his astronaut duties.

Discovery completed 112 orbits of the Earth before landing at Edwards Air Force Base, California, on September 3, 1985.

In March of that year Fisher gained political notice "when he publicly accused his superiors at the space agency of ignoring the maintenance problem.

[8] This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration.