Dianne Feinstein was first elected to the San Francisco Board of Supervisors, marking the beginning of her political career. This role allowed her to engage directly with local issues and establish her presence in city government.

She served multiple terms as President of the Board of Supervisors, a leadership role that gave her significant influence over city policy and administration.

Following the tragic assassinations of Mayor George Moscone and Supervisor Harvey Milk, Feinstein, as President of the Board of Supervisors, became Mayor of San Francisco. This period was marked by immense grief and political instability, requiring strong leadership to guide the city through a crisis.

Feinstein served as Mayor of San Francisco for ten years, navigating complex urban issues, including the AIDS crisis, infrastructure development, and economic challenges. She is often credited with revitalizing the city's economy and improving its image.