Koopmans-de Wet House is a former residence and current museum in Strand Street, Cape Town, South Africa. The house became part of the South African Museum in 1913 and was opened to the public on 10 March 1914. It was declared a National Monument under National Monuments Council legislation on 1 November 1940. It is the oldest house museum in South Africa.

Strand Street is one of the oldest and widest streets in Cape Town. Between 1664 and 1702 Strand Street was spoken of as Zee Straat. A Dutch East India Company (VOC) record of 1704 refers to it as Breete Strand Straat, while another calls it Breete Opgaande Straat no. I. In 1790 the matter was settled and name-boards with Strand Straat affixed to the corner houses.