Incumbent mayor Harley E. Knox did not stand for reelection.

Incumbent Mayor Harley E. Knox chose not stand for reelection on the advice of his physician.

Because no candidate received a majority of the vote, Crary and Butler advanced to a runoff election.

On April 17, 1951, Butler received 59.6 percent of the vote in the runoff and was elected to the office of the mayor.

[3] Butler was the youngest mayor to have been elected as well as the first to be born in San Diego.