The Castlewood Canyon State Park is a state park and recreation area in Franktown, Colorado. It is also quite historic for containing the Castlewood Canyon Dam.

Established in 1964, the Castlewood Canyon State Park is best noted by many for being a little known spot, making it less crowded and more attractive to those looking for some quiet time with friends and loved ones. The site offers 2621 acres of area, with tons of nature trails that are perfect for running and hiking. Rock climbing is also popularly enjoyed at the park, as well as picnicking. Its natural setting also tends to pull visitors in with its rich plant life and unusual geology.

The Castlewood Canyon State Park is a day use park. Camping is not allowed at the site.