The Groot Marico River is a river in South Africa. The river rises east of Swartruggens, and forms the provincial border between the North West and Limpopo provinces. It also forms the border between South Africa and Botswana. North of Johannesburg the Groot Marico River joins the Crocodile River on the border of South Africa and Botswana and becomes the Limpopo River.
Dams in it's catchment area include the Marico-Bosveld Dam, Kromellenboog Dam, Uitkyk Dam and Molatedi Dam.