| Election Name: | 1912 South Australian state election |
| Country: | South Australia |
| Type: | parliamentary |
| Ongoing: | no |
| Previous Election: | 1910 South Australian state election |
| Previous Year: | 1910 |
| Next Election: | 1915 South Australian state election |
| Next Year: | 1915 |
| Seats For Election: | All 40 seats in the South Australian House of Assembly 21 seats were needed for a majority |
| Leader1: | Archibald Peake |
| Leader Since1: | 5 June 1909 |
| Party1: | Liberal Union (Australia) |
| Leaders Seat1: | Victoria and Albert |
| Percentage1: | 51.41% |
| Swing1: | 1.83 |
| Last Election1: | 20 seats |
| Seats1: | 24 seats |
| Seat Change1: | 4 |
| Leader2: | John Verran |
| Leader Since2: | 5 June 1909 |
| Party2: | Australian Labor Party (South Australian Branch) |
| Leaders Seat2: | Wallaroo |
| Percentage2: | 46.77% |
| Swing2: | 2.32 |
| Last Election2: | 22 seats |
| Seats2: | 16 seats |
| Seat Change2: | 6 |
| Premier | |
| Before Election: | John Verran |
| Before Party: | Australian Labor Party (South Australian Branch) |
| After Election: | Archibald Peake |
| After Party: | Liberal Union (Australia) |
State elections were held in South Australia on 10 February 1912. All 40 seats in the South Australian House of Assembly were up for election. The incumbent United Labor Party government led by Premier of South Australia John Verran was defeated by the opposition Liberal Union led by Leader of the Opposition Archibald Peake. Each of the 13 districts elected multiple members, with voters casting multiple votes.
| Party | Votes | % | Swing | Seats | Change | |||
| bgcolor=blue | Liberal Union | 278,277 | 51.41 | +1.83 | 24 | +4 | ||
| bgcolor=red | United Labor Party | 253,163 | 46.77 | -2.32 | 16 | -6 | ||
| bgcolor=gray | Independent | 9,817 | 1.81 | +0.49 | 0 | 0 | ||
| Total | 541,257 | 40 | -2 | |||||
| bgcolor=blue | Liberal Union | Win | 24 | +4 | ||||
| bgcolor=red | United Labor Party | 16 | -6 |