Frik du Preez (Frederick Christoffel Hendrik du Preez) (born 28 November 1935) is a former Northern Transvaal and Springbok Rugby Union player. He was born in the town of Rustenburg, South Africa and went to school at the Parys High School in Parys (Orange Free State). Du Preez mostly played in the flank or lock positions.

Du Preez played his first test for the Springbok Rugby Team on 7 January 1961 at the age of 25 in the flank position against England at Twickenham, London. He played his last test on 7 August 1971 at the age of 35 as lock against Australia at the Sydney Cricket Ground, Sydney.

As expression of the esteem that he is held in by South African rugby fans, he was named the country’s rugby player of the twentieth century.