Hales was educated in Kensington and then at Orpington before attending Corpus Christi College, Cambridge (or St Benedict's as it was then known) in 1696. Although he was an ordinand studying divinity, Hales would have received his degree in the Classics, mathematics, natural sciences and philosophy while in Cambridge. Hales was admitted as a Fellow of Corpus Christi in 1703, the same year as he obtained the degree of Master of Arts, and was ordained as Deacon at Bugden, Cambridgeshire. He continued his theological and other studies in Cambridge, where he became friends with William Stukeley who was studying medicine. He attended chemistry lectures by Giovanni Francisco Vigani while at Cambridge. His interest in biology, botany and physiology is presumed to date from that time.