| Election Name: | 1948 South African Senate election |
| Country: | Union of South Africa |
| Type: | Parliamentary |
| Vote Type: | Popular |
| Ongoing: | no |
| Previous Election: | 1939 South African Senate election |
| Previous Year: | 1939 |
| Next Election: | 1955 South African Senate election |
| Next Year: | 1955 |
| Seats For Election: | 36 of 44 seats in the Senate |
| Majority Seats: | 23 |
| Leader1: | D. F. Malan |
| Party1: | Reunited National Party |
| Last Election1: | Did not stand |
| Seats1: | 11 |
| Seat Change1: | N/A |
| Percentage1: | 25% |
| Leader2: | Jan Smuts |
| Party2: | United Party (South Africa) |
| Last Election2: | 20 seats |
| Seats2: | 15 |
| Seat Change2: | 5 |
| Percentage2: | 34.09% |
| Map Size: | 300px |
For the fifth Senate of South Africa, the eight nominated Senators were appointed on July 28, 1948 and the Electoral Colleges met in the provincial capitals the following day. At the end of this process the government had 22 supporters (Reunited National Party 11, Afrikaner Party 2, Independent 1 and the 8 nominated Senators) and the opposition 21 (United Party 15, Labour Party 3, and Native Representatives 3). The fourth Native Representative seat was vacant.[1]
The South West Africa Affairs Amendment Act 1949 added four additional members to the Senate, of whom two were to be elected, and two nominated by the Governor-General.[2] The elected Senators were chosen by an Electoral College, composed of the members of South-West Africa's Legislative Assembly and the six members of the House of Assembly representing the territory.[3]
Of the nominated Senators, one was to be selected mainly on the ground of his "thorough acquaintance, by reason of his official experience or otherwise, with the reasonable wants and wishes or the coloured races of the territory".[4] All four Senators chosen on 29 September 1950 were National Party supporters.[5]