Sir John Spencer (c. 1455 – 14 April 1522)[1] was an English nobleman who was widely admired, in his time, for his administration of the family estates.

[2] The Spencers were granted a coat of arms in 1504, "Azure a fess Ermine between 6 sea-mews' heads erased Argent", which bears no resemblance to that used by the family after around 1595.

Spencer first made a living by trading in livestock and other commodities and eventually saved enough money to purchase the manors of Wormleighton and Althorp.

In 1513, he appointed Thomas Heritage to be rector of the church, who had previously been chaplain to King Henry VII and surveyor of the monarch's works at Westminster Abbey.

It is altogether probable that Heritage designed and superintended the execution of Spencer's idea for a family chapel at the parish church.