Monterey State Historic Park is a historic state park in Monterey, California. It includes part or all of the Monterey Old Town Historic District, a historic district that includes 17 contributing buildings and was declared a National Historic Landmark in 1970. The grounds include California's first theatre, and the Monterey Custom House, where the American flag was first raised over California.

Monterey is a city in Monterey County on the southern edge of Monterey Bay on the U.S. state of California's Central Coast. Founded on June 3, 1770, it functioned as the capital of Alta California under both Spain (1804–1821) and Mexico (1822–1846). During this period, Monterey hosted California's first theater, public building, public library, publicly funded school, printing press, and newspaper. It was originally the only port of entry for all taxable goods in California. In 1846, during the Mexican–American War of 1846–1848, the United States Flag was raised over the Customs House. After Mexico ceded California to the U.S. at the end of the war, Monterey hosted California's first constitutional convention in 1849.