| Election Name: | 1947 San Diego mayoral election |
| Flag Image: | Flag of San Diego, California.svg |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1943 San Diego mayoral election |
| Previous Year: | 1943 |
| Next Election: | 1951 San Diego mayoral election |
| Next Year: | 1951 |
| Nominee1: | Harley E. Knox |
| Party1: | Republican Party (US) |
| Popular Vote1: | 27,432 |
| Percentage1: | 67.9% |
| Nominee2: | Edgar F. Hastings |
| Party2: | Nonpartisan candidate |
| Popular Vote2: | 8,134 |
| Percentage2: | 20.1% |
| Mayor | |
| Before Election: | Harley E. Knox |
| Before Party: | Republican Party (US) |
| After Election: | Harley E. Knox |
| After Party: | Republican Party (US) |
The 1947 San Diego mayoral election was held on March 11, 1947 to elect the mayor for San Diego. Incumbent mayor Harley E. Knox stood for reelection to a second term. In the primary election, Knox received a majority of the votes and was elected outright with no need for a runoff.
Incumbent Mayor Harley E. Knox stood for reelection to a second term. On March 11, 1947, Knox received a majority of 67.9 percent of the vote in the primary election. This was more than 47 percent higher than what was received by Edgar F. Hastings, his nearest competitor. Because Knox was elected outright in the primary, no runoff election was held.
Because Knox received a majority of the votes in the primary, no general election was held.