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 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 part of 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.