1931 in South Africa

• Monarch: King George V.
• Governor-General:
  • Jacob de Villiers (until 26 January).
  • The Earl of Clarendon (starting 26 January)
• Prime Minister: James Barry Munnik Hertzog.
• Chief Justice: Jacob de Villiers.

January

• 26 – George Villiers, 6th Earl of Clarendon, is appointed the 5th Governor-General of the Union of South Africa.

December

• 11 – The Statute of Westminster establishes a status of legislative equality between the self-governing dominions of the Commonwealth of Australia, Canada, Irish Free State, Dominion of Newfoundland, Dominion of New Zealand and Union of South Africa.

• 21 January – Joseph Engenas Matlhakanye Lekganyane, founder of the St Engenas Zion Christian Church.
• 26 February – Isaac Lesiba Maphotho, anti-apartheid activist. (d. 2019)
• 10 March – Raymond Ackerman, businessman, founder of Pick 'n Pay supermarket group.
• 19 April – Kobie Coetsee, politician, in Ladybrand. (d. 2000)
• 5 July – Ismail Mahomed, South African and Namibian Chief Justice. (d. 2000)
• 15 July – Gene Louw, politician.
• 27 September – Thandi Klaasen, jazz musician (d. 2017).
• 4 October – Basil D'Oliveira, cricketer (d. 2011)
• 7 October – Desmond Tutu, social rights activist and Anglican bishop, in Klerksdorp (d. 2021).
• 24 November – Arthur Chaskalson, President of the Constitutional Court of South Africa & Chief Justice of South Africa.
• 12 December – Jafta Masemola, anti-apartheid activist. (d. 1994)
• 31 December – Dorothy Nyembe, activist and politician (d. 1998).

• 9 January – Second Boer War General Johannes Gerhardus Celliers at age 70.
• 24 January – Sir Percy FitzPatrick, author, politician and mining financier. (b. 1862)
• 24 October – Sir Murray Bisset, South African cricketer and Governor of Southern Rhodesia (b. 1876)

Railway lines opened

• 3 June – Cape – Molteno to Jamestown, 41 miles 72 chains (67.4 kilometres).^[1]
• 1 July – Natal – Chailey to Mount Alida, 25 miles 33 chains (40.9 kilometres).^[1]
• 1 July – Natal – Greyville Cabin to Berea Road, 1 mile 36 chains (2.3 kilometres).^[1]

Locomotives

Two new narrow gauge steam locomotive types enter service on the South African Railways (SAR):

• A single light Class NG G14 2-6-2+2-6-2 Garratt locomotive.^[2]
• Three 2-8-2 Mikado locomotives for the Otavi Mining and Railway Company in South West Africa. In 1960 they would become the Class NG15 Apple Express Kalaharis on the narrow gauge Avontuur Railway.^[2]

Rugby

• 19 December – The South African Springboks beat Ireland 8–3 in Ireland.