Guy I (died 1095) was the second lord of Bray and the second lord of Montlhéry (Latin: Monte Leterico). He was probably the son of Thibaud of Montmorency, but some sources say that his father was named Milo. Thibaud may instead have been his grandfather.
He married Hodierna of Gometz, sister of William, lord of Gometz. They had seven children:
Guy died in 1095, the same year Pope Urban II launched the First Crusade. Many of his descendants had illustrious careers in the Holy Land, through the Montlhéry, Courtenay, and Le Puiset branches of his family. See the Houses of Montlhéry and Le Puiset.
La Monte, John L. (January 1942). "The Lords of Le Puiset on the Crusades". Speculum.