The town takes its name from the farm De Doorns boven aan de Hex Rivier (‘the thorns on the upper Hex River’), known as early as 1725.
The De Doorns farm was bought by the government of Cape Prime Minister John Molteno in 1875, to build a railway station for the rapidly expanding Cape Government Railways. The line was immediately built through De Doorns, connecting it to Cape Town on the coast and reaching Montagu Road(later Touws River) in 1877, on its way to Kimberley. Around the station, the hamlet of De Doorns would later develop.
A village management board was instituted for De Doorns in 1933 and municipal status attained in 1951.