Rock Island Trail State Park, Rail trail in Pleasant Hill to Windsor section, Missouri.

Rock Island Trail State Park is a rail trail in rural Missouri that runs along the bed of a former railroad line, linking several small towns between Pleasant Hill in the west and Windsor in the east. The surface and surroundings shift along the way, moving through prairies, farmland, woodland, and creek crossings.

The trail runs on the embargoed, out-of-service right-of-way of the Chicago, Rock Island and Pacific Railroad between Pleasant Hill in Cass County and Windsor in Henry County, where it meets the Katy Trail. The completed trail opened on December 10, 2016. In May 2016 Jackson County acquired 17.7 miles of Union Pacific right-of-way from the Truman Sports Complex to southern Lee's Summit to bring the route toward Kansas City; work began in 2017 and the first half opened in 2018.

The trail is named for the Chicago, Rock Island and Pacific Railroad, whose embargoed right-of-way between Pleasant Hill and Windsor became the path. Near the route, the tall steel lattice tower with a blue vertical section, a gray cylindrical silo and a metal bin with a conical roof stand beside the gravel surface, remnants of the corridor's working past.

Five entry points at Pleasant Hill, Medford, Chilhowee, Leeton, and Windsor each have parking and welcome walkers, cyclists, and horse riders. The path is flat and mostly open, so sun exposure can be strong in summer, and shade is limited along certain stretches.

The trail's western end at Pleasant Hill sits at mile marker 262.9, while Windsor, where it meets the Katy Trail, is at 216.5. A 17.7-mile section bought from Union Pacific in 2016 is meant to bring the route into Kansas City, but a gap remains between Lee's Summit/Greenwood and Pleasant Hill.