Venerable Louis of Granada (1504–1588) was a Spanish Dominican theologian, preacher, and spiritual writer. His 49 works have been translated into 25 languages and published in 6,000 editions.

The Venerable Louis of Granada was born at Granada, Spain to poor descent in 1505. When he was nineteen, he became a Dominican for the convent of Santa Cruz, and subsequently served quite successfully as a preacher for forty years. He was a holy, learned, and wise man who published various works on Scripture, ethics, dogma, and Church history throughout his lifetime. His famous Sinner's Guide was originally published in 1555, and is now regarded as a spiritual classic. Also the author of The Book of Prayer and Meditation, he lived to be eighty-four years old. Louis died on the thirty-first of December, 1588, at Portugal.