1923 in South Africa

• Monarch: King George V.
• Governor-General and High Commissioner for Southern Africa:
  • Prince Arthur of Connaught (until 5 December).^[1]
  • Sir James Rose Innes (acting, from 5 December).
• Prime Minister: Jan Smuts.
• Chief Justice: Sir James Rose Innes.

March

• 1 – The Electricity Supply Commission (Eskom), largest electricity producer in Africa, is established.

Unknown date

• The South African Native National Congress changes its name to African National Congress.

• 10 April – John Watkins, cricketer (d. 2021)
• 30 April – Francis Tucker, rally Driver. (d. 2008)
• 19 May – Johannes Meintjes, artist and writer. (d. 1980)
• 6 August – Moira Lister, South African-born English film, stage and television actress. (d. 2007)
• 5 October – Glynis Johns, South African-born Welsh actress. (d. 2024)
• 11 October – Moses Mabhida, anti-apartheid activist. (d. 1986)
• 11 November – Pieter van der Byl, politician (d. 1999)
• 20 November – Nadine Gordimer, writer and political activist. (d. 2014)
• 17 December – Wilton Mkwayi, anti-apartheid activist. (d. 2004)

• 10 October – Herman Gottfried Breijer, Dutch-born South African naturalist

Railway lines opened

• 12 April – Transvaal – Dunswart to Apex deviation, 4 miles 16 chains (6.8 kilometres).^[2]
• 21 May – Natal – Queen's Bridge to Duff's Road deviation, 5 miles 55 chains (9.2 kilometres).^[2]
• 8 July – Natal – Canelands, Umdloti to Maidstone deviation, 6 miles 74 chains (11.1 kilometres).^[2]
• 6 August – Cape – Kamfersdam to Winter's Rush, 34 miles 29 chains (55.3 kilometres).^[2]
• 9 August – Cape – Belmont to Douglas, 53 miles 22 chains (85.7 kilometres).^[2]
• 30 October – Transvaal – Settlers to Tuinplaas, 13 miles 22 chains (21.4 kilometres).^[2]

Locomotives

• The New Cape Central Railway places two 2-6-2+2-6-2 Double Prairie type Garratt articulated steam locomotives in service. They will be designated Class GK on the South African Railways (SAR) in 1925.^[3][4][5]
• Major Frank Dutton, SAR Signal Engineer and the Motor Transport Superintendent, conducts trials with a prototype petrol-paraffin powered Dutton road-rail tractor.^[5][6]
• Mr. C. Lawson, Superintendent Mechanical of the SAR, experiments with gas-electric motive power and constructs a single experimental producer gas-electric locomotive. The locomotive remains in service for several years but the gas-electric concept will eventually be superseded by diesel-electric traction.^[5][6][7]