COL Mark O’Donnell was commissioned in the Infantry upon graduation from the United States Military Academy in 1990. His first assignment was in 2nd Battalion, 1st Infantry Regiment, 9th Infantry Division at Ft. Lewis, Washington, where he served as a Platoon Leader and Support Platoon Leader. COL O’Donnell continued to serve as the Support Platoon Leader as the unit reflagged as the 3rd Squadron, 2nd ACR and conducted a unit move to Ft. Polk, Louisiana. After completion of the Infantry Officer Advanced Course (IOAC) in 1994, COL O’Donnell served as an Assistant Operations Officer and B Company Commander in 1-325 Airborne Infantry Regiment, 2nd Brigade, 82nd Airborne Division. Later, he served as the Battalion Adjutant and HHC Commander in the 1st Battalion, 75th Ranger Regiment.
Following completion of the Command and General Staff College (CGSC), COL O’Donnell served as a Battalion S3 and XO in 2nd Battalion, 1st Infantry Regiment, 172nd Sep Infantry Brigade at Ft. Wainwright, Alaska. This was followed by an assignment at the United States Army Special Operations Command (USASOC) as the Chief, Ranger Operations. After two years at USASOC, COL O’Donnell was assigned to the 75th Ranger Regiment where he served as the Regimental S3 from 2005-2007.
COL O’Donnell commanded 1st Battalion, 32nd Infantry Regiment, 3 BCT, 10th Mountain Division at Ft. Drum, New York, and deployed the battalion to Konar Province, Afghanistan in support of Operation Enduring Freedom. Later, he served as the Commander of 3rd Battalion, 75th Ranger Regiment. In 2011, COL O'Donnell assumed duties as the Deputy Commander of the 75th Ranger Regiment. In 2013, COL O’Donnell graduated from the Army War College at Carlisle, Pennsylvania. COL O’Donnell then commanded 1st BCT, 10th Mountain Division (LI) at Ft Drum, New York.
COL O’Donnell has deployed six times to either Iraq or Afghanistan in support of the Global War on Terrorism. Most recently he deployed as the Commander of a Joint Special Operations Task Force, responsible for conducting counter terrorism (CT) operations across all four regional commands within Afghanistan.
COL O’Donnell holds a Bachelor of Science from the United States Military Academy, a Masters in Military Arts and Science from the Command and General Staff College, and a Masters in Security Studies from the United States Army War College. He is a graduate of the following schools: Airborne, Ranger, Sapper Leader Course, Jumpmaster Course, IOBC, IOAC, CAS3, Command and General Staff College, and the Army War College.
COL O’Donnell’s awards and decorations include: Legion of Merit, Bronze Star Medal (with 2 oak leaf clusters), the Meritorious Service Medal (with 6 oak leaf clusters), Army Commendation Medal, Army Achievement Medal (with 8 oak leaf clusters), Armed Forces Expeditionary Medal, Humanitarian Service Ribbon, National Defense Service Medal (second award), Overseas Service Ribbon, Afghanistan Campaign Medal, Iraq Campaign Medal, NATO Medal, Expert Infantryman’s Badge, Combat Infantryman’s Badge, Master Parachutist Badge, Sapper Tab, Ranger Tab, and German, Australian, and Korean Jump Wings.