During the 1930s, the British consumers would not buy the fat carcasses of the indigenous South African fat tailed breeds, so the need became apparent for a new breed of sheep in South Africa. Various breeds were combined during a series of trials where exotic mutton breeds were crossed with the indigenous species of South Africa. The Dorset Horn and Blackhead Persian cross proved very successful resulting in a breed which had a continuous breeding season, disease resistance, excellent mothering abilities, requiring little maintenance and producing good quality low fat meat. All of these traits resulted in good economic returns. The breed also had the adaptability to cope with the harsh conditions of South Africa.

A few breeders focused on breeding a white sheep, which resulted from the Dorset Horn, Blackhead Persian cross and in some cases the Dorset Horn, Van Rooy cross. This new breed was called the White Dorper.

The Dorper Breed Society of South Africa was formed in 1950, and the Dorsian (White Dorper) Breed Society affiliated with the Dorper Breed Society of South Africa in 1964.

The Dorper sheep are now the largest breed in South Africa with numbers in excess of 10 million.

The first importation of White Dorpers into Australia from South Africa was in 1997 as embryos, by South Australian and Western Australian breeders.