The culture of California, also referred to as Californian culture, encompasses various social norms, traditions, and customs in California, including literature, music, visual arts, performing arts, food, sports, religion, law, alongside other beliefs and cultural expressions. Californian culture has been shaped by the history of California, its geography, and various other internal and external factors.

Californian culture is intimately connected to the larger culture of the United States, as well as the cultures of Mexico and Spain, which both ruled California prior to its becoming a part of the United States following the American conquest of California. California is considered an international gateway to the United States and has been heavily influenced by immigration, with the various cultures of Asia and Latin America having left their mark on California's cultural landscape.

In terms of current socio-cultural mores and national politics, Californians are perceived as more liberal than most other Americans living in any other state, especially to those who live in the coastal or northern regions of California. The state, as a whole, is perceived as very liberal, voting for the Democratic Party with supermajorities, although the northeast region (predominantly the area covering the California half of the proposed State of Jefferson) consisting of more rural, mountainous, and inland areas as well as certain parts of the southern coastal region (i.e. Orange County) are conservative. California is also home to prestigious universities including Stanford University, the California Institute of Technology, the University of California, the University of Southern California, and the Claremont Colleges.

California was first settled by Indigenous tribes and the names of many cities in California are of Indigenous roots. Spain had explored the present state during the 16th century, although it did not colonize it and did not exert its cultural influence in earnest until the 18th century. By the 19th century, Spain had built missions throughout the state and California consisted of huge land extensions (called "ranchos"). Indigenous cultures, though significantly damaged, survived to some extent by adapting to European influences in the missions. From that time to the present, Hispanic Californians have always been among the largest cultural groups in the state. Furthermore, Mexican immigration into California has also resulted in a large share of cultural contributions, with critics labeling this phenomenon Mexifornia.

Around the time of California's 1850 statehood, Mexicans and indigenous people were seen somewhat negatively by the incoming American population due to economic competition as well as racist attitudes. The California Gold Rush of the 1850s is now seen as a symbol of California's modern economic style, a pioneering spirit that tends to generate technology, social ventures, entertainment, and economic fads and booms that, in many cases, are followed all around the globe. Southern California, having not experienced the migration boom of the gold rush, became less Americanized than northern California. A growing Asian presence and the advocacy of black Californians also contributed to a unique Californian cultural and political scene.

California has long been a subject of interest in the public mind and has often been promoted by its boosters as a kind of paradise. In the early 20th Century, fueled by the efforts of state and local boosters, many Americans saw the Golden State as an ideal resort destination, sunny and dry year round with easy access to the ocean, deserts, and mountains. In the 1960s, popular music groups such as the Beach Boys promoted the image of Californians as laid-back, tanned beach-goers. The hippie movement began in San Francisco, California in the early 1960s and progressed into the late 1970s.

English is the main language of California's inhabitants. Spanish is a common second language throughout the state. The official language of California has been English since the passage of Proposition 63 in 1986. However, many state, city, and local government agencies print official public documents in Spanish and other languages since Proposition 63 doesn't regulate how governments use other languages. Spanish was the official administrative language in California through the Spanish and Mexican periods until 1848, when Alta California was ceded from Mexico to the United States following the U.S. Conquest of California. Early American governments in California protected the rights of Spanish speakers in the 1849 Constitution of California, but those constitutional protections were removed in 1879.

California English is a dialect of the English language spoken within California. California is the home to a highly diverse populace, and this is reflected in many other languages, especially Spanish. Not all features of California English are used by all speakers in the state, and not all features are restricted in use only to the state. However, there are some linguistic features which can be identified as either originally or predominantly Californian. As the nation's major motion picture and television entertainment center, Hollywood has influenced English throughout the world, by making English speakers of many dialects very visible and by making known new terms and new meanings. The media outlets and entertainment industry based in California also popularizes the California English accent and dialect to the rest of the country and the world.