Irnham is a village and civil parish in South Kesteven, Lincolnshire, England.

The village is on a high limestone ridge that forms part of the Kesteven Uplands.

The civil parish of Irnham includes the hamlets of Bulby and Hawthorpe.

The similar extent ecclesiastical parish is Irnham, part of the Beltisloe rural deanery in the Diocese of Lincoln, and part of a Group which includes Corby Glen and Swayfield, sharing a single priest.

[8] St Andrew's Church is late Norman with Perpendicular additions, and was heavily restored in 1858, and again in 2006.