Billinghay is a village and civil parish in the North Kesteven district of Lincolnshire, England. The village is situated approximately north-east from Sleaford, and lies on the B1189 Walcott road near its junction with the A153. Just south of the village towards Sleaford is North Kyme. According to the 2001 census the parish had a population of 1,808.
The settlement is mentioned in the Domesday Book. The name originates from a Saxon name for a fishery. The topography in ancient times would have been that of a small settlement on a gravel mound surrounded by marsh which was flooded in winter. After the draining of the fens in the late 18th century the area became rich agricultural land as it is today. The parish church is of historic interest. It dates from the 13th century.
After the phased closure of Lafford High School due to falling pupil numbers, Billinghay Primary School remains the only school in the village.