| Election Name: | 1905 San Diego mayoral election |
| Flag Image: | Flag of San Diego, California.svg |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1903 San Diego mayoral election |
| Previous Year: | 1903 |
| Next Election: | 1907 San Diego mayoral election |
| Next Year: | 1907 |
| Nominee1: | John L. Sehon |
| Party1: | Democratic Party (US) |
| Popular Vote1: | 2,018 |
| Percentage1: | 52.7% |
| Nominee2: | Dan F. Jones |
| Party2: | Republican Party (US) |
| Popular Vote2: | 1,376 |
| Percentage2: | 35.9% |
| Mayor | |
| Before Election: | Frank P. Frary |
| Before Party: | Republican Party (US) |
| After Election: | John L. Sehon |
| After Party: | Democratic Party (US) |
The 1905 San Diego mayoral election was held on April 4, 1905, to elect the mayor of San Diego. John L. Sehon was elected mayor with a majority of the votes.
Incumbent Mayor Frank P. Frary declined to run for reelection. Three candidates campaigned for the open seat: Dan Jones, a Republican, John L. Sehon, a Democrat running on the Non-Partisan ticket, and W.J. Kirkwood, a Socialist.
On April 4, 1905, Sehon was elected mayor with a majority of 52.7 percent of the vote. Jones came in second with 35.9 percent of the vote. Kirkwood came in third with 11.3 percent.
During the campaign, it was questioned whether a retired army officer such as Sehon was eligible for civil office. Fearing that his opponents would attempt to lock him out of office, Sehon broke into City Hall in the middle of the night of the first day of his term to forcibly take possession of the office of the mayor.