LOSTWITHIEL, a market-town of England, county of Cornwall, on the River Fowey, 5 miles S.S.E. from Bodmin. Its streets are narrow and roughly paved; and its houses are generally built of stone, and roofed with slate. The principal building is the parish church, a structure of the fourteenth century, surmounted by a spire, and containing a curiously ornamented old font. During the civil war, having been used as a barrack by the parliamentary troops, it was injured by an explosion of gunpowder. Near the church is the site of the ancient palace of the earls of Cornwall, now occupied by the stannary prison. There are also three dissenting chapels. Many of the population are employed in tanning, lime-burning, and the woollen manufacture. A considerable trade is carried on in lime, coals, iron, and timber. About a mile from the town are the fine ruins of Restormel Castle, another palace of the earls of Cornwall. Lostwithiel once returned two members to Parliament, but was disfranchised by the Reform Act. Pop. of parish (1851) 1053.