Coastal California refers to the coastal regions of the US state of California. The term is not primarily geographical as it also describes an area distinguished by cultural, economical and political attributes. The coastal regions of California tend to be more politically liberal, affluent and expensive than other regions of the state.^{[citation needed]}

Nearly all congressional districts in the region are left-leaning with a mean Cook Partisan Voting Index of D +13.3, meaning that a Democratic presidential candidate will, on average, be 13.3 percentage points ahead of his Republican opponent. The Cook Partisan Index in coastal California ranges from D +9 in California's 23rd congressional district, which includes coastal San Luis Obispo county to D +20 in the 30th district, which includes Malibu, West Los Angeles and Beverly Hills, to D +36 in Nancy Pelosi's 8th district, which includes most of San Francisco.

In contrast with most coastal counties of California, only Del Norte County, San Luis Obispo County, Ventura County, Orange County, and San Diego County voted for incumbent Republican president George W. Bush in 2004. San Francisco County, the most Democratic county, voted 83% for Kerry. In 2008, only Del Norte and Orange Counties voted for John McCain with margins of less than 5% while San Francisco remained the most Democratic county, voting 84% for Barack Obama.

California (pronounced ⁱ/kælɨˈfɔrnjə/) is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third most extensive (after Alaska and Texas). It is home to the nation's second- and sixth-largest census statistical areas (Los Angeles Metropolitan Area and San Francisco Bay Area), and eight of the nation's fifty most populated cities (Los Angeles, San Diego, San Jose, San Francisco, Fresno, Sacramento, Long Beach and Oakland). The capital city is Sacramento.

California's diverse geography ranges from the Pacific Coast in the west, to the Sierra Nevada mountains in the east – from the Redwood–Douglas-fir forests of the northwest, to the Mojave Desert areas in the southeast. The center of the state is dominated by Central Valley, a major agricultural area. California contains both the highest and lowest points in the contiguous United States (Mount Whitney and Death Valley), and has the third-longest coastline of all states (after Alaska and Florida). Earthquakes are a common occurrence due to the state's location along the Pacific Ring of Fire: about 37,000 are recorded annually.