In his will he founded the Henry Lucas Charity with a bequest of £7000, to be spent on building an almshouse for poor old men and on employing a chaplain as its Master.
He also bequeathed his collection of 4000 books (including Galileo's Dialogo of 1632) to the University Library, along with enough land to give an income of £100 a year, which was to be used to fund a professorship of "mathematick" (now the Lucasian Professorship of Mathematics).