Following the murder of Mayor George Moscone, Dianne Feinstein becomes San Francisco's first female mayor.

On November 27, 1978, George Moscone, the 37th mayor of San Francisco and Harvey Milk, a member of the San Francisco Board of Supervisors, were both shot and killed inside San Francisco City Hall by former supervisor Dan White. On the morning of that day, Moscone intended to announce that the Supervisor position from which White had previously resigned would be given to someone else. White, angered, entered City Hall before the scheduled announcement and first shot Moscone in the Mayor's office, then Milk in White's former office space, before escaping the building. Board of Supervisors President Dianne Feinstein first announced Moscone and Milk's deaths to the media, and because of Moscone's death, succeeded him as acting mayor.

Dianne Emiel Feinstein was an American politician who served as a United States senator from California from 1992 until her death in 2023. A member of the Democratic Party, she served as the 38th mayor of San Francisco from 1978 to 1988.

San Francisco, officially the City and County of San Francisco, is a commercial, financial, and cultural center of Northern California. With a population of 827,526 residents as of 2024, San Francisco is the fourth-most populous city in the U.S. state of California and the 17th-most populous in the United States. San Francisco has a land area of 46.9 square miles at the upper end of the San Francisco Peninsula and is the fifth-most densely populated U.S. county. Among U.S. cities proper with over 250,000 residents, San Francisco is ranked first by per capita income and sixth by aggregate income as of 2023. San Francisco anchors the 13th-most populous metropolitan statistical area in the U.S., with almost 4.6 million residents in 2023. The larger San Jose–San Francisco–Oakland combined statistical area, the fifth-largest urban region in the U.S., had a 2023 estimated population of over nine million.