New Hampshire Route 4 is a 3.78-mile (6.08 km) state highway located in eastern Strafford County, New Hampshire. Its western terminus is at an intersection with New Hampshire Route 9 and New Hampshire Route 108 in Dover. Its northern terminus is at the Maine state border in Rollinsford, where it continues as Maine State Route 4. For most of its length NH 4 is signed as an east-west highway. Signage in downtown Dover while overlapped with NH 9 and NH 108 is inconsistent as it is sometimes signed north-south. In general, NH 4 follows a southwest-to-northeast alignment.