urban district and seaport on the southern border of County Louth (Louth), Ireland. Drogheda lies along the River Boyne (Boyne, River) about 4 miles (6.5 km) from its mouth. Drogheda was a stronghold and trading post of the Norsemen in the 8th–11th century and of the Anglo-Normans in the 12th century. Two towns grew up, one on either side of the river; they received separate incorporation in 1228 but were combined by charter in 1412. In the reign of Edward III it was a staple town (by royal fiat, a trade and export centre), and several medieval parliaments met there. In 1649 it fell to Oliver Cromwell (Cromwell, Oliver), and its inhabitants were massacred. It ceased to be a parliamentary borough in 1885 and a county of itself in 1898.

The remains of the ancient fortifications comprise the St. Lawrence Gate and the West Gate. Other remains are the tower of a Dominican friary (founded 1224) and the arch of an Augustinian abbey (founded 1206). In St. Peter's Church, a shrine contains the embalmed head of the archbishop of Armagh, St. Oliver Plunket (Plunket, Saint Oliver), who was martyred in London in 1681. The district's industry includes linen and cotton mills, coach-building works, flour mills and sawmills, a brewery, a large cement works, and the manufacture of pipes, fats, soaps, medical equipment, and agricultural machinery.

Drogheda is the centre for salmon fishing on the River Boyne, and agricultural produce and coal are traded by sea. Pop. (2006) 28,973.