Long Sutton is a market town and civil parish in the South Holland district of Lincolnshire, England. It lies in The Fens, close to the Wash, 13 mi…Long Sutton is a market town and civil parish in the South Holland district of Lincolnshire, England. It lies in The Fens, close to the Wash, 13 miles east of Spalding. In 2011 the parish had a population of 4,821.