Maidstone State Park, State park on Maidstone Lake, Vermont, United States.

Maidstone State Park is a Vermont state park on the south and east shores of 796-acre Maidstone Lake, a glacial lake in the Northeast Kingdom town of Maidstone. It has two parts: a 40-acre day-use area with a beach, picnic ground and CCC-built pavilion, and a 600-acre camping parcel about a mile south with tent/RV sites and lean-tos.

Maidstone State Park was developed in 1938 by the Civilian Conservation Corps, a Depression-era jobs program, and was among the last Vermont state parks built by the CCC. The corps erected a day-use area with a pavilion, a nature center, fourteen stone fireplaces and a parking lot, reflecting the rise of automobile vacation travel. A major infrastructure upgrade followed in the late 1970s, yet the park kept the look of its early years.

The park's name comes from Maidstone, the town in Essex County that hosts it, in Vermont's Northeast Kingdom. The Civilian Conservation Corps built the day-use pavilion, a nature center and fourteen stone fireplaces, and some of the lean-tos, so the 1930s work is still visible to visitors. Camping is split between 34 tent and RV sites and 37 lean-tos.

The park has two separate areas reached by Maidstone Lake Road: a day-use area with beach and picnic pavilion, and a camping parcel about one mile south with 34 tent/RV sites and 37 lean-tos, hot showers and a sanitary dump station. It is open from Memorial Day weekend to Columbus Day weekend, and fees apply for day use and camping.

The lake supports a population of lake trout that thrive in its deep, cold waters. The water body formed around 12,000 years ago through glacial processes, giving it ecological character.