Lieutenant Colonel Sean Walsh enlisted in the United States Marine Corps Reserve in July of 1986 as an Anti-Tank Infantry Assaultman. Upon graduation from Marine Corps Recruit Depot San Diego and Infantry Training School; he joined Weapons Company 3rd Battalion, 24th Marines located in St Louis Missouri. From 1986-2000, he served with Weapons and Kilo Company holding a variety of billets to include Section Leader, Squad Leader, Platoon Sergeant and Platoon Commander, achieving the rank of Staff Sergeant. During this time, he deployed in support of Operation DESERT STORM/SHIELD, graduated from the University of Missouri-St Louis, and worked as a Special Education Teacher for St Louis Special School District and The Epworth School.
In January 2000, he attended Officer Candidates School and was commissioned a Second Lieutenant upon graduation. Following the Basic School, he attended the Logistics Officers Course where he received orders to 1st Marine Division, Camp Pendleton, CA. In February of 2001, he joined Truck Company, Headquarters and Service Battalion and served as a Platoon Commander and Company Executive Officer. In June 2002, he reported to 2nd Battalion, 1st Marines as the Motor Transport Officer and deployed to Operation IRAQI FREEDOM I with BLT 2/1. Upon his return from Iraq, he reported to 1st Marine Regiment as the Regimental S-4A and deployed to Operations IRAQI FREEDOM II with Regimental Combat Team-1.
In August 2004, he reported to Marine Corps Recruit Depot Parris Island and was promoted to Captain. From 2004-2007, Captain Walsh served as Property Control Director and the Installation and Logistics (G-4) Operations Officer.
In 2007, Captain Walsh attended Expeditionary Warfare School and upon graduation in 2008, he reported to Marine Wing Support Squadron 372 as the Motor Transport Company Commander. In 2009, he transitioned to the Squadron Operations Officer and deployed in support of Operation ENDURING FREEDOM in Afghanistan.
In June of 2010, he reported to Expeditionary Strike Group Two at Joint Expeditionary Base-Little Creek in Virginia and was promoted to rank of Major. From 2010 to July 2013, he served as the N4 Logistics Planner participating in multiple Bold Alligator exercises working on a Navy Staff.
In 2013, Major Walsh attended Marine Corps Command and Staff College in Quantico, graduating with distinction.
In July of 2014, Major Walsh reported to Camp Lejeune and was assigned as the Regimental Operations Officer for Combat Logistics Regiment 2. In June of 2016, Major Walsh was selected to serve as the Logistics Officer for the II MEF Advise and Assist Team in support of Operation INHERENT RESOLVE and was part of Task Force Al Taqaddum in Iraq from December 2016 to August 2017. During that time, he was promoted to his current rank.
Lieutenant Colonel Walsh holds a Bachelors Degree in Special Education-Behavior Disorders from the University of Missouri St Louis and a Master's Degree in Military Studies from Marine Corps University. His personal decorations include Meritorious Service Medal, Navy and Marine Corps Commendation Medal with a gold star, Navy Achievement Medal with V device and a gold star, and the Combat Action Ribbon.