The Judiciary of California is defined under the California Constitution, law, and regulations as part of the Government of California. The judiciary has a hierarchical structure with the Supreme Court at the apex, California courts of appeal as the primary appellate courts, and the California superior courts as the primary trial courts.

Its administration is effected by the Judicial Council and its staff, as well as the relatively autonomous courts. California uses a modified Missouri Plan (merit plan) method of appointing judges, whereby judges are nominally elected at the superior court level (but in practice are first appointed by the Governor) and appointed at higher levels, and are subject to retention elections.

The judicial system of California is the largest in the United States that is fully staffed by professional law-trained judges. As of 2012, the state judiciary has more than 2,000 judicial officers that hear over 10 million cases each year (with the assistance of 21,000 staff members.) In comparison, the federal judicial system has only about 840 judges. Although New York and Texas each technically have more judicial officers than California, a large number of them are not attorneys and have no formal legal training.

Unlike the state supreme court, the courts of appeal have mandatory review jurisdiction under the informal legal tradition in common law countries that all litigants are entitled to at least one appeal.

The California courts of appeal are the intermediate appellate courts. The state is geographically divided into six appellate districts, Notably, all published California appellate decisions are binding on all superior courts, regardless of appellate district. the First Appellate District in San Francisco, the Second District in Los Angeles, the Third District in Sacramento, the Fourth District in San Diego, the Fifth District in Fresno, and the Sixth District in San Jose. The districts are further divided into 19 divisions sitting throughout the state at 9 locations, and there are 105 justices serving on the Courts.

In California, the power of the intermediate courts of appeal over the superior courts is quite different from the power of the courts of appeals of the federal government over the federal district courts. The first Court of Appeal to rule on a new legal issue will bind all lower superior courts statewide. However, litigants in other appellate districts may still appeal a superior court’s adverse ruling to their own Court of Appeal, which has the power to fashion a different rule.