Northern California
—  Megaregion of the U.S.  —
San Francisco
San Jose
Sacramento
Country	United States
State	California
Population (2010)	14,573,946

Yosemite Valley in the Sierra Nevada.

Northern California is the northern portion of the U.S. state of California. The San Francisco Bay Area (which includes the cities of San Francisco, Oakland, and the largest city of the region, San Jose), and Sacramento (the state capital) as well as its metropolitan area are the main population centers. It also contains redwood forests, along with the Sierra Nevada including Yosemite Valley and Lake Tahoe, Mount Shasta (the second-highest peak in the Cascade Range after Mount Rainier in Washington), and the northern half of the Central Valley, one of the world's most productive agricultural regions.

The area also contains one of the 11 megaregions of the United States, spanning from the San Francisco Bay Area east to the Lake Tahoe-Reno area, and from Metropolitan Fresno north to Greater Sacramento.

Native Americans arrived in Northern California at least as early as 8,000 to 5,000 BC and perhaps even much before, and successive waves of arrivals led to one of the most densely populated areas of pre-Columbian North America. The arrival of European explorers from the early 16th to the mid-18th centuries, did not establish European settlements in Northern California. In 1770, the Spanish mission at Monterey was the first European settlement in the area, followed by other missions along the coast—eventually extending as far north as Sonoma County.