Trawsfyndd nuclear power station is a disused Magnox power station situated at Trawsfynydd in Gwynedd, Wales.
Construction of the power station, which was undertaken by a consortium involving Crompton Parkinson, International Combustion, Fairey Engineering and Richardsons Westgarth, and known as the Atomic Power Constructions (APC), began in July 1959, and both of the reactors were in operation by March 1965, with the station opening fully in October 1968, at a cost of £103 million. It had two Magnox reactors producing 470 megawatts (MW) in total. The reactors were supplied by APC and the turbines by Richardsons Westgarth. The civil engineering work was undertaken by Holland, Hannen & Cubitts and Trollope & Colls. The architectural consultant for the buildings was Sir Basil Spence and the landscape architect was Sylvia Crowe. 
Both have been shut down since 1991; the site is in the process of being decommissioned by the Nuclear Decommissioning Authority.