Brian Bagley was selected for a Naval Reserve Officers’ Training scholarship and enrolled at Marquette University in Milwaukee, Wisconsin. He graduated with a Bachelor of Science in Mechanical Engineering. Following training at The Basic School in Quantico, Virginia, he attended the Aviation Supply Officer Basic Qualification Course in Athens, Georgia.
Second Lieutenant Bagley then reported to Marine Aviation Logistics Squadron 29 at Marine Corps Air Station New River, North Carolina where he served as the Consumables Management, Repairables Management, and Supply Response Division Officer in Charge. From January 2007 to February 2008, he supported OPERATION IRAQI FREEDOM in Al Asad, Iraq.
In June 2009, First Lieutenant Bagley was ordered to Marine Helicopter Squadron One (HMX-1) in Quantico, Virginia, where he served as the Assistant Aviation Supply Officer and Fiscal Officer.
In May 2013, Captain Bagley was selected to attend Naval Postgraduate School where he earned a Master of Science in Operations Research.
In June 2015, Captain Bagley was ordered to Marine Corps Logistics Command in Albany, Georgia where he served as an Operations Research Analyst.
In June 2018, Major Bagley was ordered to Marine Aviation Logistics Squadron 36 in Okinawa, Japan, where he served as the Aviation Supply Officer and Executive Officer. Then in May 2020, Major Bagley reported to Headquarters and Support Battalion where he served as the Company A, Company Commander. In July 2021, Major Bagley reported to 3rd Marine Expeditionary Brigade where he served as the Information Management Officer.
In December 2021, Lieutenant Colonel Bagley was ordered to Marine Aircraft Group 14 where he served as the Personnel Support Detachment Commanding Officer.
On 16 June 2022, Lieutenant Colonel Bagley took command of Marine Aviation Logistics Squadron 14.
Lieutenant Colonel Bagley is a graduate of Expeditionary Warfare School, Command and Staff College, Legal Officers Course, and Security Managers Course. His decorations include a Meritorious Service Medal, Navy and Marine Corps Commendation Medal (2 stars), and Navy and Marine Corps Achievement Medal (1 star).