Lieutenant Colonel Littlejohn was born in Washington, D.C. He earned a Bachelor of Science in Applied Mathematics from Norfolk State University and commissioned in the United States Marine Corps in 2008.
Following The Basic School, he completed the Field Artillery Officer Basic Course at Fort Sill, Oklahoma. In May 2010, he reported to 2d Battalion, 11th Marines, where he served as a Forward Observer and an Artillery Liaison Officer. In 2011, he deployed to Helmand Province, Afghanistan, in support of Operation Enduring Freedom as a Forward Observer attached to Company K, 3d Battalion, 4th Marines.
In December 2011, he was reassigned as the Executive Officer for Battery S, 5th Battalion, 11th Marines. From June 2012 to February 2013, he deployed with Battery S, a reinforced composite artillery Battery employing HIMARS, cannons, and radar systems, in support of Operation ENDURING FREEDOM across Helmand Province, Afghanistan.
From June 2013 to September 2015, Lieutenant Colonel Littlejohn attended the Naval Postgraduate School, where he earned a Master of Science in Electrical Engineering and received the 8824 AMOS. During this period, he completed Expeditionary Warfare School through the Distance Education Program and Command and Staff College (Joint PME Phase I) through the U.S. Naval War College Monterey Campus.
In October 2015, he reported to Marine Corps Tactical Systems Support Activity, where he served as the Fire Support Systems Technical Support Officer. In this role, he supported multiple Marine Corps Systems Command programs in developmental testing, systems integration, and evaluation of fire support and C4I systems.
In March 2017, he reported to 2d Battalion, 11th Marines, where he served as the Assistant Operations Officer. He was subsequently selected to attend the Marine Corps Tactical Operations Group’s Operations and Tactics Instructor Course, earning the 0577 AMOS.
He assumed command of Battery R, 5th Battalion, 11th Marines in November 2017 and deployed the unit to Okinawa. Japan from May to November 2018 as part of the Unit Deployment Program under 3d Battalion, 12th Marines, 3d Marine Division. Following command, he served as the Battalion Operations Officer for 5th Battalion, 11th Marines.
In 2020, Lieutenant Colonel Littlejohn was selected to command Recruiting Station Fort Lauderdale, where he served until 2023. Following this assignment, he reported to United States Special Operations Command for a joint tour, where he managed Emergent Global Force Management and subsequently served as the Executive Officer to the Chief of Staff.