Lake Chabot Regional Park is a regional park located in the southern Berkeley Hills in Alameda County, California. It was opened to the public on June 18, 1966, as part of the East Bay Regional Parks system. Lake Chabot is a reservoir located in the park. The northern part of the lake and park lie within the boundary of the city of Oakland, while the southern part lies in an unincorporated area of Alameda County adjacent to Castro Valley and San Leandro.