Round Lake State Park is a public recreation area located four miles (6.4 km) southwest of Sagle in Bonner County, Idaho.

The 142-acre (57 ha) state park surrounds 55-acre (22 ha) Round Lake.

[3] The lake was formed from glacial activity in the Pleistocene.

[4] The park offers campsites, fishing, swimming, boating for non-motor and electric-powered watercraft, and trails for hiking, biking and skiing.

[5] This state park is home to black bear, moose, grizzly bear, waterfowl, beaver, various songbirds, and deer.