Old Town San Diego State Historic Park, Historic state park in San Diego, United States.

Old Town San Diego State Historic Park is a historic state park in central San Diego that contains a collection of restored 19th-century buildings, museums, and period-style shops spread over several city blocks. The adobe structures cluster around a central plaza, where courtyards with arcades, wrought-iron fencing, and cobbled pathways recreate the early California townscape.

The town grew at the base of Presidio Hill in the 1820s, after the Spanish presidio founded there by Gaspar de Portolà in 1769 was abandoned. San Diego received pueblo status from the Mexican government in 1834, lost it in 1838, and became the county seat in 1850 with 650 residents. Government records moved to Alonzo Horton's New Town in 1871, and the site became a state park in 1968.

The park keeps the Mexican-era town alive: the Mexican Commercial Corner hosts locally based small businesses and artists, and living history demonstrations and free tours run on a regular schedule. Restaurants in and around the park are known for Mexican food, and the 1889 Templo Beth Israel building, one of the oldest synagogues in the United States, is open to visitors and used for exhibitions and weddings.

Admission to the grounds and most museums is free, and exhibition hours typically run from 10 AM to 5 PM. Guided walking tours led by costumed interpreters take place several times a day and offer insights into the daily life of early residents.

Five of the adobe buildings are original structures from the early settlement and have never been demolished or replaced, including the Casa de Estudillo, which is a National Historic Landmark. One of the buildings houses an old brick oven that still works and has been in use since the 1830s, occasionally fired up for demonstrations.