Guy Étienne Germain Gaucher, OCD (5 March 1930 – 3 July 2014) was a French Catholic Discalced Carmelite bishop and theologian. He served as Bishop of Meaux and was an international authority on the life and writings of Thérèse of Lisieux.

Born in Tournan-en-Brie, he was ordained a priest on 17 March 1963 and made his religious profession into the order of Discalced Carmelites on 3 October 1968. He was named Bishop of Meaux, 27 August 1986, consecrated on 19 October 1986 by the archbishop of Paris, cardinal Jean-Marie Lustiger. A few months later, 7 May 1987, he was named auxiliary bishop of Bayeux-Lisieux in residence at Lisieux. He remained in this post until 1 July 2005 at which time he retired having reached the age limit.^[1]

At first a specialist in the writings of Georges Bernanos, he subsequently devoted his attention to the personality and writings of Thérèse of Lisieux.^[2] Amongst his many editorial works, he notably participated in the centenary Edition of the works of Thérèse.^[3]

Gaucher died on 3 July 2014 at the age of 84.^[4]

• Gaucher, Guy. The Story of a Life: St. Thérèse of Lisieux. San Francisco: Harper & Row, 1987. ISBN 978-0-06-063095-9 Over copies in US libraries, according to WorldCat
  • Review, Catholic Historical Review, Apr., 1989, vol. 75, no. 2, p. 304-305
• Gaucher, Guy. John and Thérèse: Flames of Love : the Influence of St. John of the Cross in the Life and Writings of St. Thérèse of Lisieux. Staten Island, N.Y.: Alba House, 1999.
• Thérèse, Guy Gaucher, and Aletheia Kane. The Prayers of Saint Thérèse of Lisieux: The Act of Oblation. Washington, DC: ICS Publications, 1997.
• Gaucher, Guy. The Passion of Thérèse of Lisieux: 4 April - 30 September 1897. New York: Crossroad, 1990.
• Gaucher, Guy. I Would Like To Travel the World: Thérèse of Lisieux: Miracle-Worker, Doctor, and Missionary. Sophia Institute Press, 2023.