The Fourth Reich (El Cuatro Reich) is a 1990 South African biographical drama film directed by Manie van Rensburg and co-produced by Gert Basson, Mark Jaffee, David Selvan, Bill Shapter and Reg Wessels for Zastron Films. The film stars an ensemble South Africa cast, with Ryno Hattingh starring in the lead as Robey Leibbrandt. Supporting cast included Marius Weyers, Grethe Fox and Percy Sieff. Also supporting were many popular South African dramatists.

The film revolves around the life of Robey Leibbrandt, a South African boxer who participated in the 1936 Olympic Games in Berlin. While at the Games he was courted by the Nazis in an attempt to recruit him as an agent in South Africa. Leibbrandt embraced Nazi ideology, which culminated in his becoming an Abwehr agent for the Third Reich. As an Abwehr agent in 1939, Leibbrandt led an operation to overthrow the South African pro-Allied government, and to assassinate General Jan Smuts, at the time Prime Minister of the Union of South Africa.

The Fourth Reich was the most expensive film production in South African cinema history.

The Fourth Reich played well at international film festivals and received widespread acclaim and positive reviews.