The Lake Ouachita State Park is a state park and recreation area in Mountain Pine, Arkansas. It lies within the Ouachita Mountains and the Ouachita National Forest.

Named after and featuring the Lake Ouachita, the Lake Ouachita State Park traces its roots back to 1875, when it was still owned by homesteader John McFadden. The site was home to the ?Three Sisters?, a cluster of three springs that were once believed to have curative properties. The site then became the Three Sisters Spring Resort and was quite a tourist destination. By the 1950s, efforts to preserve the historic tourist attraction started, and became the birth of the current state park.

Today, visitors of the Lake Ouachita State Park can enjoy not only the scenic beauty of the site, but also picnicking, camping, hiking, boating, and swimming among other things.