Castro Adobe, Historic adobe house in Watsonville, United States.

Castro Adobe is a two-story earthen building in Santa Cruz County, California, with wide verandas that look out over the surrounding valley. It is one of the few surviving examples of Mexican rancho-style construction in this part of the state.

Juan José Castro built the two-story adobe between 1848 and 1849 on Rancho San Andrés, the Mexican land grant his father José Joaquín Castro had received in the Pájaro Valley. It is the only two-story hacienda ever built in Santa Cruz County. It was listed on the National Register of Historic Places on December 12, 1976, and is California Historical Landmark number 998.

The upper floor contains a large room once used for fandango evenings, a social tradition common on California ranchos at the time. These gatherings brought together families and neighbors for music and dancing, and the room still reflects that open, festive purpose.

The building is not open every day, and visits are typically arranged through scheduled open house events that include guided tours. Checking availability in advance is a good idea before planning a trip out to the site.

The adobe is the only two-story hacienda ever built in Santa Cruz County, and it holds the county's first dance floor, the fandango room. Volunteers and the California Conservation Corps began restoring it in August 2007 by making 2,500 adobe bricks. Almost 100 members of the Castro family held a reunion at the site in 2008.