Benicia State Recreation Area, State recreation area in Solano County, California.

Benicia State Recreation Area is a nature preserve in Solano County featuring salt marshes, grassy hillsides, and rocky shoreline along the Carquinez Strait. The site provides walking paths and viewpoints overlooking the water, with open spaces for visitors to explore the landscape on foot.

The area was originally home to Native American peoples before undergoing industrial use in later periods. It was eventually restored and established as a protected state recreation area.

The name Southampton Bay comes from the Navy frigate Southampton, which Commodore Thomas ap Catesby Jones brought into the cove with a small fleet in 1849. An earlier Spanish name, Puerto de las Asunta, was given by Don José de Cañizares, who found the cove on that feast day in 1775 and marked it as "J" on his 1781 map of San Francisco Bay. The Forrest Deaner Native Plants Botanic Garden at the end of the picnic area displays Bay Area native plants.

The site is open daily from dawn until sunset, with parking fees required upon arrival. Restrooms, picnic tables, and trash facilities are available for visitors planning to spend the day here.

The park's 1,000-foot-thick Southampton mudflat formed from eroded upriver silt and clay. California golden beavers, likely descended from animals that moved in from the Sacramento–San Joaquin Delta around 2007, live in the park. The endangered salt marsh harvest mouse also inhabits the marsh.