Born at Coventry, he was the son of Thomas Tillesley of Eccleshall in Staffordshire, by his wife, the daughter of Richard Barker of Shropshire.
It is stated by Anthony à Wood that he was one of three who undertook to answer John Selden's book: he and Richard Montagu were to dealing with the legal part, and Stephen Nettles with the rabbinical aspect.
Like Montagu in his Diatribe upon the first part of the late "History of Tithes," Tillesley discussed the historical aspect of the controversy in depth.
Passing over the question of Jewish tithes, which had already been dealt with by Sir James Sempill, he traced their history from the apostolic period, and endeavoured to show that they had been continuously and universally enjoined by divine law.
A second edition of the work was published in 1621, and contained an additional essay on some philological passages in Selden's book.