Rock Island is an unincorporated town in the northeastern-most portion of Warren County, Tennessee, United States. The town was named after a small island that existed at the confluence of the Collins River and Caney Fork River before the erection of Great Falls Dam. Rock Island is home to Rock Island State Park. Many different houses, restaurants, and marinas can be found here. Rock Island is a popular destination during the summer season. Boats can often be seen on the river riding by. The state park offers many different hiking trails as well as a sand bar (almost a beach front).