Cromwell is a town in Middlesex County, Connecticut, United States located in the middle of the state. The population was 12,871 at the 2000 census. The town was named after Oliver Cromwell, Lord Protector of the Commonwealth of England. A major north/south highway, Interstate 91, with two Cromwell exits, runs through the Town. The Central Connecticut Expressway (Route 9), opened at the end of 1989, enhances the Town's location as it connects I-95 in Old Saybrook, I-91 in Cromwell and I-84, the State's major east/west highway in New Britain.