Lieutenant Colonel Michael J. Gagnon graduated from Framingham State College with a Bachelor of Science in Business Administration, with a concentration Management, in 2005. He was commissioned upon completing Officer Candidate School in August 2007. Second Lieutenant Gagnon completed training at The Basic School and Logistics Officers Course where he was designated a 0402, Logistics Officer.
Upon graduation from Logistics Officers Course, Second Lieutenant Gagnon reported to Marine Wing Support Squadron 371 in Yuma, Arizona. From August 2008 to June 2012, where he served as an Assistant Logistics Officer, Logistics Officer, Assistant Operations Officer, Motor Transport Platoon Commander, and Motor Transport Company Executive Officer.
From March 2009 to May 2012, Second Lieutenant Gagnon deployed to Afghanistan in support of Operation Enduring Freedom 09.1, 10.2, and 11.2 enabling the establishment of expeditionary airfields and helicopter landing zones, oversaw expeditionary airfield operations, and served as a Logistics Advisor to the Afghan Border Police. In March 2009 and October 2011, he was promoted to the rank of First Lieutenant and Captain, respectively.
In July 2012, Captain Gagnon reported to the Expeditionary Warfare School in Quantico, Virginia. Upon graduating in May 2013, he executed orders to 2d Battalion, 1st Marine Regiment and served as the battalion's Logistics Officer. From July 2014 to February 2015, Captain Gagnon deployed with Battalion Landing Team 2/1 in support of 11th Marine Expeditionary Unit's Western Pacific 2014 deployment.
In June 2015, Captain Gagnon executed orders to Combat Logistics Battalion 1 in Camp Pendleton, California and served as the Transportation Services Company Commander.
In August 2016, Captain Gagnon reported to U.S. Marine Corps Forces, Europe and Africa in Stuttgart, Germany and served as the G-4 Materiel Readiness Officer. In July 2017, he transitioned to the G-4 Operations and Plans Department to serve as a Logistics Planner. In September 2017, he was promoted to the rank of Major.
In August 2019, Major Gagnon was assigned to Combat Logistics Battalion 7 in Twenty-nine Palms, California to serve as the battalion's Executive Officer. From February to September 2021, he deployed to Darwin, Australia as the Logistics Combat Element's Executive Officer in support of Marine Rotational Force - Darwin 21.2.
In June 2022, Major Gagnon reported to the Marine Corps' Command and Staff College. In June 2023, he graduated with a master’s degree in military studies and was awarded Distinguished Graduate. Upon graduating, he executed orders to 1st Marine Logistics Group to serve as the G-3 Operations Officer. In August 2023, he was promoted to the rank of Lieutenant Colonel. From November 2023 to June 2024, he deployed to Qatar as the Special Operations Joint Task Force - Central J-4 Director. From June 2024 to June 2026, he executed orders to Combat Logistics Regiment 1 in Camp Pendleton, California and served as the regiment's Executive Officer.
On 16 July 2026, LtCol Gagnon assumed command of Logistics Operations School, Camp Johnson, North Carolina.