The official Twitter account of Cretin-Derham Hall. News and Announcements from Cretin-Derham Hall, a co-educational Catholic high school committed to affordable academic excellence. Cretin-Derham Hall is a Catholic co-educational high school, co-sponsored by the Brothers of the Christian Schools and the Sisters of St. Joseph of Carondelet, committed to Christian values and academic excellence in grades nine through twelve. We will educate young men and women of diverse abilities, cultures, and socioeconomic backgrounds for opportunities in post-secondary education.