Command Sergeant Major (Retired)  Mario O. Terenas, U.S. Army, joined the Association of the U.S. Army in September of 2022. He serves as the Deputy Director of AUSA's Center for Leadership.

A native of Lisbon, Portugal, Mario moved to the United States at 16 to reside with his American mother. He enlisted in the U.S. Army in 1990, attending basic training and advanced individual training as an 11B (infantryman) at Fort Benning, Georgia.

During his 32-year career, Mario held every enlisted leadership position in a variety of Airborne, Stryker, Mechanized, and Light Infantry units, ranging from Team Leader to Division Command Sergeant Major. Mario served in the 2nd Infantry Division, 5th Infantry Division, 1st Cavalry Division, 101st Airborne Division, and 10th Mountain Division. As a Command Sergeant Major, he served as the CSM for the 3rd Battalion, 6th Field Artillery, Fort Drum, NY, CSM for the National Training Center "Tarantula" OC/T team, Fort Irwin, CA, Commandant of the 8th Army NCO Academy, Camp Jackson, South Korea, CSM for the U.S. Operational Test Command, Fort Hood Texas, CSM for the U.S. Cadet Command & Fort Knox, KY. He culminated as the CSM for the 10th Mountain Division, Fort Drum, NY.

Mario is a graduate of all levels of the NCO professional development schooling culminating in the Nominative Leader's course. In addition, he is a graduate of the Joint Forces Key Stone course, the NCO Academy pre-commandants course, and the Battalion & Brigade pre-command courses.

In addition to four tours in the Republic of South Korea, Mario deployed in support of Operation Iraqi Freedom twice in 2003 and 2005 and in support of Operation Enduring Freedom in 2009.

Mario is a graduate of class 61 of the U.S. Army Sergeants Major Academy and the Command Sergeants Major Course. Mario holds a Bachelor of Science in Leadership Management (Summa Cum Laude) from Trident University.

Mario has been married to his wife, Kelly, for 24 years. They have two daughters, Alechandra, a United States Military Academy graduate and an Engineer Lieutenant in the 2nd Brigade 101st ABN DIV, and Sofia, a freshman at Millersville University, studying computer science.