Bordering Rocky Hill to the north is Wethersfield, with Newington to the northwest, Berlin to the southwest, and Cromwell to the south. The Connecticut River forms the eastern border. Interstate 91 runs through the town with exits at the two main local highways, Route 3 at exit 23 and Route 99 at exit 24. Route 3 travels from Cromwell through Rocky Hill into Wethersfield, eventually crossing the Connecticut River into Glastonbury. The north-south Route 99 parallels the Connecticut River for the length of town.