Chatteris, a market town in the Wisbech parliamentary division of Cambridgeshire, England, 25½ m. N. by W. of Cambridge by the Great Eastern railway. Pop. of urban district (1901) 4711. It lies in the midst of the flat Fen country. The church of St Peter is principally Decorated; and there are fragments of a Benedictine convent founded in the 10th century and rebuilt after fire in the first half of the 14th. The town has breweries, and engineering and rope-making works. To the north runs the great Forty-foot Drain, also called Vermuyden’s, after the Dutch engineer whose name is associated with the fen drainage works of the middle of the 17th century.