Helen Putnam Regional Park, Regional park in Petaluma, United States.

Helen Putnam Regional Park is a large open space in Petaluma with rolling grass hills and scattered oak groves. The path system connects different areas of the land and offers views across multiple counties.

The park is named after Helen Putnam, a former teacher who served as Petaluma's first female mayor from 1966 to 1978 and later sat on the Sonoma County Board of Supervisors. In 1975 she led the city's fight to control urban growth limits; developers sued, and the case reached the Supreme Court, which let stand a Ninth Circuit ruling upholding Petaluma's aim to keep its small-town character and open space. The park was officially dedicated in 1985.

The park draws hikers, cyclists, and riders who share the trails throughout the year. It serves as a place where different outdoor activities coexist peacefully on the same land.

The main lot at 411 Chileno Valley Road holds 37 spaces, with bays for handicapped and equestrian users; a second lot with 31 spaces and bike parking opened in 2021 at 373 Windsor Drive, at the West Wind Trailhead. A gazebo, picnic area and children's playground stand near the main lot, beside a pond stocked with bluegill. Trails are shared by hikers, cyclists and riders, and include a segment of the Bay Area Ridge Trail.

The Ridge Trail has two parallel routes between the parking area and Cattail Pond with different surfaces. One path is paved while the other follows natural ground, giving visitors a choice based on their needs.