Districts in California geographically divide the U.S. state into overlapping regions for political and administrative purposes.
History of California political districts
From the founding of the state until 2008, the responsibility of redrawing the state's Congressional, Assembly, Senate, and Board of Equalization districts had been exercised by the California state legislature.
In November 2008, California voters passed Proposition 11, the Voters FIRST Act, which took political redistricting responsibility away from the state legislature and instead established a 14-member statewide redistricting commission composed of five Republicans, five Democrats, and four not affiliated with either of those two parties but registered with another party or as decline-to-state. The California Citizens Redistricting Commission was initially charged with updating the state assembly, senate, and Board of Equalization district boundaries starting with the 2010 census. Another initiative, Proposition 20, passed in 2010, expanded the Commission responsibilities to also include the state Congressional districts.
Congressional districts
California is divided into 52 Congressional districts.
Each district elects a representative to serve in the United States House of Representatives as part of the California's congressional delegation.
California's current districts were drawn in 2021 by a California Citizens Redistricting Commission. The new boundaries took effect for the June 7, 2022 primary.
State legislative districts
State Senate districts
California is divided into 40 State Senate districts, each of which elects a senator to the State Senate. Twice the size of an Assembly district, each senate district contains about 931,000 people. The combined Senate roster is available from . The members of the California Senate Republican caucus are listed at .
Prior to 1968, state senate districts were restricted such that one county could only hold at most one seat. This led to the situation of Los Angeles County, with 6 million residents as of 1968, receiving 600 times less representation than residents of Alpine County and Calaveras County, some of California's least populous counties. The Reynolds v. Sims decision by the United States Supreme Court compelled all states to draw up districts that were apportioned by population rather than geography. As such, boundaries were changed such that equal representation was provided.
State Assembly districts
California is divided into 80 State Assembly districts, each of which elects a member to the State Assembly. Each assembly district contains about 466,000 people. Each Assembly member is limited to three terms by a referendum passed by California voters. In March 2008, Proposition 93 unsuccessfully attempted to change term limits to a maximum of twelve years or six terms instead of three.
The California Assembly Democratic Caucus members are listed at . The California Assembly Republican Caucus members are listed at .
California Appellate Court districts
The California Court of Appeal is divided into six appellate districts, based on geography. Some of the appellate districts are further divided into Divisions.
First District
The California Court of Appeal for the First District is located in San Francisco. Its jurisdiction is over the following counties: Alameda, Contra Costa, Del Norte, Humboldt, Lake, Marin, Mendocino, Napa, San Francisco, San Mateo, Solano, and Sonoma. It is divided into five non-geographical divisions with four justices each.
Second District
The California Court of Appeal for the Second District has its main courthouse in Los Angeles and the secondary courthouse, hosting Division Six, in Ventura. Division Six handles appeals from San Luis Obispo, Santa Barbara, and Ventura Counties, while Divisions One through Five, Seven, and Eight handle appeals from Los Angeles County. Each division has four justices.
Third District
The California Court of Appeal for the Third District is located in Sacramento. Its jurisdiction is over the following counties: Alpine, Amador, Butte, Calaveras, Colusa, El Dorado, Glenn, Lassen, Modoc, Mono, Nevada, Placer, Plumas, Sacramento, San Joaquin, Shasta, Sierra, Siskiyou, Sutter, Tehama, Trinity, Yolo, and Yuba. It has 11 justices and is not divided into divisions.
Fourth District
The California Court of Appeal for the Fourth District is unique in that it is divided into three geographical divisions that are administratively separate, which even have different case number systems, and yet remain referred to as a single district.
