Slangfontein was a farm in the Free State, north west of Dewetsdorp.

On 19 September 1901 Commandant J. Ackerman came across a force of British soldiers burning the farm house. Taken completely by surprise, the British force were forced to surrender, with six men killed, 15 wounded and 100 taken prisoner. Two guns as well as rifles and ammunition were taken by the Boers.