Market Deeping is a market town and civil parish in the South Kesteven district of Lincolnshire, England, on the north bank of the River Welland and the A15 road. The population of the town at the 2011 census was 6,008.

A market town is a settlement most common in Europe that obtained by custom or royal charter, in the Middle Ages, a market right, which allowed it to host a regular market; this distinguished it from a village or city. In Britain, small rural towns with a hinterland of villages are still commonly called market towns, as sometimes reflected in their names.