Marmion Academy (formerly Marmion Military Academy) is a grade 9–12 Roman Catholic high school for boys in Aurora, Illinois, United States. It is in the Roman Catholic Diocese of Rockford. The academy is owned and operated by the Benedictine monks of Marmion Abbey on campus. The academy is known for its three pillars: Spirituality, Academics and Leadership. The unique leadership formation programs include: Leadership Education and Development (LEAD) program and a United States Army Junior Reserve Officers' Training Corps (JROTC) program that has been a part of the academy since its early years, but was not a part of the school in the inaugural year of 1933–34.