The Heysham nuclear power stations are operated by EDF Energy in Heysham, Lancashire, England. On the site two separate nuclear power stations, Heysham 1 and Heysham 2 operate independently, only with joint entry protocol, both with two reactors of the advanced gas-cooled reactor (AGR) type.

Construction of Heysham 1, which was undertaken by British Nuclear Design & Construction (BNDC),began in 1970, with the first reactor commencing operations in 1983 and the second reactor following in 1984. However, initial production levels were low, and full commercial operation was only declared in 1989. Its generating capacity is 1,150 MWe. There were four 17.5 MW auxiliary gas turbines on the site, these had been first commissioned in January 1977.

Heysham 1 shares its reactor design with Hartlepool nuclear power station, which introduced the replaceable pod boiler design. The CEGB specified a compact design for the Heysham 1 and Hartlepool power station reactor islands in comparison to the design of the two preceding stations at Hinkley Point B and Hunterston B in order to reduce the capital cost, but this caused expensive construction delays because of restricted access.

Heysham 1 was scheduled to be shut down for defueling and then decommissioning in March 2024. EDF subsequently announced plans to extend the life of Heysham 1 and Hartlepool to March 2026. In December 2024, EDF further extended the life of Heysham 1 until March 2027. In September 2025, following an inspection of the graphite cores, EDF announced a further one year extension to March 2028.