A native of Barrington, Rhode Island, Lieutenant Colonel Matthew Tweedy enlisted in the Marine Corps in July of 2002. Upon completion of entry-level training at Marine Corps Recruit Depot Parris Island and Marine Combat Training, he attended the Defense Language Institute and associated cryptological schools before arriving at 2d Radio Bn. As a radio reconnaissance Marine, he completed two deployments in support of Operation Iraqi Freedom and the Global War on Terror. In 2007, he joined 2d Marine Special Operations Battalion, deploying with them in support of Operation Enduring Freedom in 2008.
Following his selection to the Marine Enlisted Commissioning Program in 2008, he attended Tufts University in Medford, Massachusetts, graduating with a Bachelor of Arts and commissioning in July 2010.
Upon completion of The Basic School and the Infantry Officer Course, he was ordered to 3d Battalion, 2d Marines, where he served as a rifle platoon commander and Combined Anti-Armor Team platoon commander, deploying with the 26th Marine Expeditionary Unit in 2013. In 2014, he was assigned to The Basic School to serve as a warfighting instructor, Staff Platoon Commander, and the director of the Instructor Education Program.
Following this assignment, he attended Expeditionary Warfare School where he received the Shipman and Geiger Awards as the top overall graduate and top combat arms graduate. After graduating in June 2018, he was assigned to 2d Battalion, 2d Marines, to serve as a rifle company commander. During this time, he participated in Exercise Trident Juncture with the 24th Marine Expeditionary Unit in 2018 and deployed to Okinawa, Japan, for the Unit Deployment Program from 2019 to 2020.
He reported to the Naval Postgraduate School in Monterey, California, in 2020, where he earned a Master of Science in Manpower Systems Analysis. From March 2022 to June 2024, he was assigned to the Capabilities Development Directorate, Combat Development and Integration. In June 2024, he reported to 2d Light Armored Reconnaissance Battalion to serve as Executive Officer and later served as the Operations Officer for 6th Marine Regiment from April 2025 to April 2026. He assumes command of 1st Battalion, 8th Marines in April 2026.
Lieutenant Colonel Tweedy is married to the former Sarah Martella of Windham, New Hampshire. They have six children.