Skylab 4 (also SL-4 and SLM-3) was the third crewed Skylab mission and placed the third and final crew aboard the first American space station.

The mission began on November 16, 1973, with the launch of Gerald P. Carr, Edward Gibson, and William R. Pogue in an Apollo command and service module on a Saturn IB rocket from the Kennedy Space Center, Florida, and lasted 84 days, one hour and 16 minutes. A total of 6,051 astronaut-utilization hours were tallied by the Skylab 4 astronauts performing scientific experiments in the areas of medical activities, solar observations, Earth resources, observation of the Comet Kohoutek and other experiments.

The crewed Skylab missions were officially designated Skylab 2, 3, and 4. Miscommunication about the numbering resulted in the mission emblems reading "Skylab I", "Skylab II", and "Skylab 3" respectively.

Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations included an orbital workshop, a solar observatory, Earth observation, and hundreds of experiments.

Unable to be re-boosted by the Space Shuttle, which was not ready until 1981, Skylab's orbit decayed, and it disintegrated in the atmosphere on July 11, 1979, scattering debris across the Indian Ocean and Western Australia.