Thomas à Kempis was a German-Dutch canon regular of the late medieval period and the author of The Imitation of Christ, one of the most popular and best known Christian devotional books. His name means "Thomas of Kempen", Kempen being his home town. While the form Thomas à Kempis is often found, it is actually incorrect. The correct Latin should be Thomas a Kempis, as borne out by surviving contemporary mentions of his name.
He was a member of the Modern Devotion, a spiritual movement during the late medieval period, and a follower of Geert Groote and Florens Radewyns, the founders of the Brethren of the Common Life.