Steyr (shtĪˈər) [key], city (1991 pop. 39,337), Upper Austria prov., central Austria, on the Enns and Steyr rivers. It has been an ironworking center since the Middle Ages. Other manufactures include trucks, automobiles, tractors, ball bearings, machinery, and guns. Among Steyr's numerous well-preserved historic buildings are Lamberg castle (10th cent.; rebuilt in the 18th cent.) and a Gothic parish church of the 15th–16th cent.