The DN postcode area, also known as the Doncaster postcode area,[2] is a group of 32 postcode districts in northern England, within 13 post towns.

These cover eastern South Yorkshire (including Doncaster), north Lincolnshire (including Grimsby, Scunthorpe, Barnetby, Barrow upon Humber, Barton-upon-Humber, Brigg, Cleethorpes, Gainsborough, Immingham and Ulceby), parts of north Nottinghamshire (including Retford) and the south-west of the East Riding of Yorkshire (including Goole), and a small part of southern North Yorkshire.

The S64 postcode district for Mexborough was earmarked as DN13, which has never been used.

Otherwise, the area's districts are numbered sequentially up to DN22, then from DN31 to DN41 for Grimsby and surrounding settlements.

The approximate coverage of the postcode districts: