John Hales (1584 - 1656) was an English theologian.

He was born at Bath, and educated there and at the University of Oxford, becoming one of the best Greek scholars of his day. He lectured on Greek language at Oxford. In 1616 he accompanied the English ambassador to the Hague as his chaplain, and attended the Synod of Dort, where he was converted from Calvinism to Arminianism. He refused all offers of ecclesiastical preferment, choosing instead a scholarly retirement in a Fellowship of Eton College, of which his friends Sir Henry Savile and Sir Henry Wotton were successively Provost. A treatise on Schism and Schismatics (1636?) gave offence to Archbishop Laud, but Hales defended himself so well that Laud made him a Prebendary of Windsor. Refusing to acknowledge Oliver Cromwell's government, he was deprived, fell into poverty, and had to sell his library. After his death his writings were published in 1659 as The Golden Remains of the Ever-Memorable Mr. John Hales of Eton College .