Doonside is a small coastal resort on the banks of the Little Manzimtoti River in KwaZulu-Natal, South Africa. It is now part of eThekwini.

Holiday resort on the Indian Ocean some 30 km south-west of Durban, between Amanzimtoti and Illovo Beach. At first the siding was called Middleton, after its builder, but to avoid confusion with Middleton in the Cape the name was changed in 1910 to Doonside, after a house called Lorna Doone which overlooked the siding