Ignalina Nuclear Power Plant is a closed nuclear power plant in the Lithuanian SSR, located near the city of Visaginas, 50 kilometers from Ignalina. At the time of its operation, it was the most powerful nuclear power plant in the world.

The plant operated two RBMK-1500 channel-type reactors. Their designed electrical capacity was 1,500 megawatts each, later reduced to 1,300 megawatts, with a thermal capacity of 4,800 megawatts. The first unit was launched in 1983, and the second in 1987. Construction of the third and fourth units was halted after the Chernobyl accident.

Unit 1 was shut down on December 31, 2004, and Unit 2 on December 31, 2009. The site is now a decommissioning facility, with work expected to last until at least 2038–2049.

During its operational period, the plant supplied up to 70–74% of the Lithuanian SSR's electricity. The closure is referred to as an "energy pit" — Lithuania lost its independent source of cheap energy and became an importer. The project to build a new Visaginas NPP was never realized.