The Monadnock State Park is a state park in Jaffrey, New Hampshire. It is considered as one of the top five state parks to see during the fall for its stunning vistas and amazing foliage.

Located in and around the National Natural Landmark, Mount Monadnock (which is why it is also sometimes referred to as Mount Monadnock State Park), the Monadnock State Park covers over five thousand acres of land area. Visitors can enjoy forty miles of foot trails for hiking, as well as plenty of space for winter recreation like skiing, and even camping. Picnicking is also a popular activity at the park.

The Monadnock Staet Park is open year round. They charge day use fees at staffed entrances as well as camping fees.