The economy of the State of California is the largest in the United States, with a $4.048 trillion gross state product (GSP) as of 2024. It is the largest sub-national economy in the world. If California were an independent nation, it would rank as the fourth largest economy in the world in nominal terms, behind Germany and ahead of Japan.
California's Silicon Valley is home to some of the world's most valuable technology companies, including Apple, Alphabet, and Nvidia. As of June 2025, 58 of the Fortune 500 companies are headquartered in California.