town and borough (district), administrative and historic county of Northumberland, England, in the northernmost portion of England.

From the 12th century, when the River Tweed became the boundary between England and Scotland, the border town of Berwick was disputed between English and Scots but, after changing hands 13 times, was finally surrendered to England in 1482. Its ramparts were originally built by Edward I, who gave the town its first English charter in 1302; rebuilt by Elizabeth I, they are in good repair, but little remains of the Norman castle, which was already in ruins when its site was encroached upon to make way for the railway station. The parish church (1648–52) is noteworthy as one of the few built during the Commonwealth. The oldest of the three bridges that cross the Tweed near Berwick dates from 1634; the modern road bridge was built in 1928. Upstream the railway is carried by the Royal Border Bridge, a striking viaduct 126 feet (38 metres) high with 28 arches, built by Robert Stephenson in 1847–50.

The mainly rural and agricultural borough extends southeastward along the North Sea coast—including Bamburgh Castle, Holy Island (Lindisfarne), and the Farne Islands—and southwestward to the Cheviot Hills. Area borough, 377 square miles (976 square km). Pop. (2001) borough, 25,948.