Dianne Goldman Berman Feinstein (pronounced /ˈfаɪnstаɪn/) (born June 22, 1933) is the senior U.S. Senator from California and a member of the Democratic Party. Feinstein was first elected to the U.S. Senate in 1992, after serving as Mayor of San Francisco from 1978 to 1988.

Feinstein holds a number of "firsts": She was the first female President of the San Francisco Board of Supervisors, San Francisco's first (and so far, only) female mayor, the first woman to serve in the Senate from California, one of two female Jewish senators (the other being Barbara Boxer), the first woman to serve on the Senate Judiciary Committee, and the first woman to chair the Senate Rules Committee and Senate Intelligence Committee.

Feinstein was born Dianne Emiel Goldman in San Francisco to Betty Rosenburg, a former model, and Leon Goldman, a nationally renowned surgeon who was the first Jew tenured as a physician at the UCSF Medical Center in San Francisco. Feinstein's paternal grandparents were Jewish immigrants from Poland, while her maternal grandparents, who were of the Russian Orthodox faith, left St. Petersburg, Russia, after the 1917 Russian Revolution; Feinstein's maternal grandfather was an imperial army officer who was a convert from Judaism to Christianity. Feinstein has two sisters, Lynne Kennedy and Yvonne Banks.