Ohlone Wilderness, Regional park in Alameda County, California, US.

Ohlone Wilderness is a regional park spanning nearly 10,000 acres across Alameda County with oak woodlands, grassy ridges, and seasonal wildflower displays. The landscape includes Rose Peak, a notable summit, and connects four separate preserves through an extensive trail network.

For generations the land was inhabited by Chochenyo-speaking Ohlone, the Taunans. The first white settlers, Patrick and Mary Ann Geary, started a homestead here in the 1860s; in 1895 their son Maurice Geary built the house and barn later used as the Interpretive Offices and Green Barn Visitors Center. Willis Brinker acquired the property in 1939, and Sunol-Ohlone Regional Wilderness opened in 1962 with 6,858 acres, the predecessor of today's Sunol and Ohlone wildernesses.

The name comes from the Chochenyo-speaking Ohlone, specifically the Taunans, who lived on this land for generations before settlers arrived. The Geary family homesteaded here in the 1860s, and their son Maurice built the house and barn in 1895; these later served as the Interpretive Offices and the Green Barn Visitors Center.

The wilderness can be crossed only on foot or on horseback; trail bicycles and motor vehicles are not allowed. The 29-mile Ohlone Wilderness Trail links Del Valle Regional Park, Sunol Regional Wilderness and Mission Peak Regional Preserve. Where the route passes through San Francisco Water Department land, users must stay within the trail boundaries or face citation and fines for trespassing.

The Ohlone Wilderness Trail crosses two parcels owned by the San Francisco Water Department, where hikers and riders must stay inside the trail corridor; straying can bring a citation and fine for trespassing and may put public use of the corridors at risk.