First Sergeant Justin H. Gardner graduated from high school in 2008 and enlisted in the United States Marine Corps, attending recruit training at Marine Corps Recruit Depot Parris Island, South Carolina. He graduated in September 2008 and subsequently attended Marine Combat Training at Camp Geiger, North Carolina. He completed follow-on schools in Pensacola, Florida, and Camp Pendleton, California, and in March 2009 was designated as an Aviation Ordnance Systems Technician (MOS 6531)
From March 2009 to June 2014, First Sergeant Gardner was assigned to Marine Light Attack Helicopter Squadron 467 (HMLA-467) in Cherry Point, North Carolina. During this time, he served as an Aviation Ordnance Technician, Collateral Duty Inspector, and Quality Assurance Safety Observer. In February 2013, he deployed with the 26th MEU.
In June 2014, he reported to Marine Aerial Refueler Transport Squadron 152 (VMGR-152) in Iwakuni, Japan, where he served as the Aviation Ordnance NCOIC.
In June 2015, First Sergeant Gardner transferred to the Center for Naval Aviation Technical Training (CNATT) in Cherry Point, North Carolina. There, he served as an Instructor, Master Training Specialist, Course Supervisor, and Chief Instructor.
In August 2018, he reported to Marine Attack Squadron 223 (VMA-223) in Cherry Point, North Carolina, and deployed to Isa Air Base, Bahrain, in support of Operation Inherent Resolve. During this assignment, he served as the Aviation Ordnance SNCOIC.
First Sergeant Gardner completed the Basic Recruiter Course in June 2021 and was assigned to Recruiting Station Harrisburg, 1st Marine Corps District. He served as a canvassing recruiter at Recruiting Substation Allentown, Pennsylvania, before transferring in March 2022 to Recruiting Substation Capital City in Harrisburg, Pennsylvania, as the SNCOIC.
In July 2024, he reported to Marine Light Attack Helicopter Squadron 773, Detachment A in New Orleans, Louisiana, where he served as the Aviation Ordnance Chief and Squadron Gunnery Sergeant.
In June 2025, First Sergeant Gardner reported to his current assignment as the Inspector-Instructor First Sergeant for Communications Detachment, Indianapolis, Indiana.
First Sergeant Gardner’s personal decorations include the Navy and Marine Corps Commendation Medal (3rd Award) and the Navy and Marine Corps Achievement Medal (6th Award).