Caistor Grammar School was founded in 1631 pursuant to the wills of the following donors:-

Francis Rawlinson , Rector of South Kelsey, who in 1630 bequeathed 400 to be vested in land, for the maintenance of a free grammar school in Caistor, provided the inhabitants would build a school house; and

Wm. Hansard
, of Buslingthorpe, who in 1627 left 250 to build the school and directed his executors to purchase lands of the yearly value of 45, and to pay 30 thereof to the master, and 15 to the usher.

The 400 left by Mr Rawlinson was laid out in purchasing the rectorial tithes of Bilsby and Asserby, which, with about five acres of land, produced about 180 per annum.

Pursuant to Hansard's bequests, an estate of 42A. 1R. 17P. was purchased at Cumberworth, to which 24A. 3R. 30P. of common land was allotted at the enclosure in 1819, and was let for about 100 per annum.

The school was free for classical and religious instruction to all boys of Caistor and the neighbouring parishes; but a small quarterage was charged for English, reading, writing and arithmetic. There was an Exhibition at Jesus College, Cambridge, for Caistor scholars.

In 1838 it was thoroughly repaired at the cost of 200, raised by subscription.

In 1857 the Lord Chancellor issued a new scheme for the future management of the school.