Ralph B. Clark Regional Park, Regional park in Orange County, United States

Ralph B. Clark Regional Park is an urban park in Buena Park and Fullerton, California, south of Rosecrans Avenue at the southern edge of the West Coyote Hills. Its main area lies south of Rosecrans, while a small section called Camel Hill and a three-softball-field section known as "The Yard" lie north of Rosecrans within Fullerton city limits. A 1.2-mile tree-shaded trail runs along the park periphery and rises to the top of Camel Hill.

Ralph B. Clark Regional Park opened in 1981 as Los Coyotes Regional Park. In 1987 it was renamed for Ralph B. Clark (1917–2009), the Orange County Supervisor who was retiring that year. The park is maintained by Orange County Regional Parks.

The Interpretive Center is a small museum with ice age fossil and local geology exhibits, including a mural of ice age mammals by Mark Hallet. Its best-known piece is a 9-million-year-old baleen whale skeleton recovered from a local construction site, reputed to be one of the only complete Miocene whale fossils in existence. It is usually open Wednesday through Saturday, 10am to 2pm, depending on staff and volunteers.

The main section south of Rosecrans Avenue charges per vehicle with no free re-entry, while parking at "The Yard" north of Rosecrans is free. The 1.2-mile perimeter trail climbs Camel Hill in the northeast corner. Fishing licenses are required for ages sixteen and up.

The park's interpretive center displays a 9-million-year-old baleen whale skeleton recovered from a local construction site, reputed to be one of the only complete Miocene whale fossils in existence. A mural of ice age mammals by Mark Hallet hangs in the same small museum.