California's 12th congressional district is a congressional district in northern California. Lateefah Simon, a Democrat, has represented the district since January 2025. The district was represented previously by longtime congresswoman Barbara Lee, former Speaker of the House of Representatives Nancy Pelosi (who has since been redistricted to the 11th district), and former president of the United States Richard Nixon.
Currently, the 12th district is located in Alameda County and encompasses the cities of Oakland, Berkeley, Emeryville, Alameda, Albany, Piedmont, and most of San Leandro. With a Cook Partisan Voter Index rating of D+39, the 12th district is the most Democratic district in California, giving nearly 85% of its vote to Kamala Harris in the 2024 presidential election.
Before redistricting in 2023, the 12th district was within San Francisco, encompassing most of the city. The remainder of the city was included in the 14th district.
When the district was created after the 1930 census, it was located in Los Angeles County. As California's population grew, however, the district generally was moved northward, eventually to the San Francisco peninsula.
Richard Nixon, who would subsequently serve as the 37th president of the United States, represented this district from 1947 to 1951, when it was located to the east of Los Angeles. Nancy Pelosi, the former speaker of the House, represented the district from 2013 to 2023, when it covered most of San Francisco. She had previously served California's 5th congressional district from 1987 to 1993 and California's 8th congressional district from 1993 to 2013 and currently represents California's 11th congressional district.
Due to the 2020 redistricting, California's 12th district has effectively been shifted to the former geography of the 13th district. It encompasses the coastal section of Alameda County, and is anchored by Oakland. The district also includes the cities of Alameda, Albany, Berkeley, Emeryville, Piedmont, and San Leandro. Technically, the westernmost tip of Alameda Island is part of the City and County of San Francisco, but it is uninhabited.
This district borders the 13th district, and Alameda County is partitioned between them by Grant Ave, Union Pacific, Lewelling Blvd, Wicks Blvd, Manor Blvd, Juniper St, Dayton Ave, Padre Ave, Fargo Ave, Edgemoor St, Trojan Ave, Beatty St, Fleming St, Highway 880, Floresta Blvd, Halcyon Dr, Hesperian Blvd, Thornally Dr, Highway 185, 150th Ave, Highway 580, Benedict Dr, San Leandro Creek, and Lake Chabot Regional Park.