Mostert's Mill is a historic windmill in Cape Town, South Africa and is the oldest surviving windmill in South Africa.
The mill was built around 1796 as a private mill on the farm 'Welgelegen', owned by Gysbert van Renen, and was named after his son-in-law, Sybrand Mostert, after Van Renen's death. It was the first privately owned mill, as prior to the British occupation of the Cape in the Battle of Muizenberg in 1795, only mills controlled by the Dutch East India Company were allowed.
The mill was first restored in 1935, and is now in working order. The Friends of Mostert's Mill operate the mill and it is open to the public on most Saturdays.
Mostert's Mill is situated on the M3 close to the University of Cape Town on the slopes of Devil's Peak where it is a prominent landmark.