Northern California megaregion

The Northern California megaregion (also Northern California Megalopolis) is an urbanized region of California consisting of many large cities in Northern California including San Jose, San Francisco, Sacramento, and Oakland. There are varying definitions of the megaregion, but it is generally seen as encompassing the San Francisco Bay Area, the Sacramento area, northern San Joaquin Valley, and the Monterey Bay Area.

The most common definition of the megaregion consists of the San Jose–San Francisco–Oakland Combined Statistical Area, the Sacramento–Roseville–Arden-Arcade Metropolitan Statistical Area, the Yuba City Metropolitan Statistical Area, the Modesto Metropolitan Statistical Area, the Merced Metropolitan Statistical Area, and the Salinas Metropolitan Area. Under this definition, the megaregion was home to 12.6 million residents in 2018, and had a GDP of $1.21 trillion, resulting in a GDP per capita of $96,029. The megaregion thus accounted for 3.9% of the U.S. population, and 5.9% of the U.S. economy in 2018.

The concept is seen as increasingly relevant in the context of a rapidly growing Northern California economy plagued by transportation issues and a lack of affordable housing.

The region is home to some of the world's highest ranked universities, including Stanford University, University of California - Berkeley, University of California - San Francisco, and University of California - Davis.