Newark-on-Trent or Newark () is a market town and civil parish in the Newark and Sherwood district of Nottinghamshire, England. It stands on the River Trent, the A1 – the ancient Great North Road – and the East Coast Main Line railway. Its origins may be Roman, as it lies on a major Roman road, the Fosse Way. A centre for the wool and cloth trades, it grew up round Newark Castle, now ruined, and a market place still lined with historic buildings. In the English Civil War, it was besieged by Parliamentary forces and relieved by Royalist forces under Prince Rupert. Today many Newark residents commute to the cities of Lincoln and Nottingham.