Rafael Arnaiz Baron
- Category : 1911-births
- Type : GP
- Profile : 4/1 - Opportunistic / Investigator
- Definition : Split - Large
- Incarnation Cross : JX Shock
Spanish Trappist conventual oblate. He studied architecture in Madrid, but decided to cease his studies in favor of the religious life. This was often interrupted due to his struggle with diabetes and his being called for active service. But these never hindered his religious call and he did as best as he could to deal with his diabetes through his constant life of reflection and writing on spiritual subjects in his letters. He died from diabetes on 26 April 1938 at age 27 in Dueñas, Palencia, Second Spanish Republic.
He was beatified on 27 September 1992 by Pope John Paul II and was canonized a saint of the Catholic Church by Pope Benedict XVI on 11 October 2009.