Gunnery Sergeant John Velez enlisted in the United States Marine Corps in September 2005 from Jersey City, New Jersey. He attended recruit training at Marine Corps Recruit Depot, Parris Island, in July 2006. Following recruit training, Private First Class Velez completed Marine Combat Training (MCT) and Administrative Specialist School.
His first duty station was with Combat Logistics Company 36 (CLC-36), Marine Corps Air Station (MCAS) Iwakuni, Japan. In 2009, Corporal Velez transferred to Marine Corps Installation West (MCIW), Marine Corps Base Camp Pendleton, California. That same year, he attended Mountain Warfare Training Center in Bridgeport, California. He also participated in exercise Cobra Gold in Pattaya, Thailand, in March 2010. Later that year in July 2010, he deployed as an Individual Augment to Doha, Qatar, returning in January 2011 having attained the rank of Sergeant.
In November 2011, Sergeant Velez reported to Wounded Warrior Battalion-East (WWBn-E), Marine Corps Liaison Office (MCLO) Bethesda, Maryland. Selected for recruiting duty, he transferred to Recruiting Station Baltimore in December 2013. Following a successful tour, Staff Sergeant Velez reported to MCAS Miramar, California, in December 2016.
In October 2017, Staff Sergeant Velez deployed to Kuwait with Special Purpose Marine Air-Ground Task Force, Crisis Response-Central Command (SP-MAGTF CR-CC) as the Administrative Chief. Upon his return in 2018, he transferred to Marine Wing Headquarters Squadron 3 (MWHS-3). He was subsequently promoted to Gunnery Sergeant and transferred to Chemical Biological Incident Response Force (CBIRF), Marine Forces Command (MARFORCOM), where he served as Personnel Officer, Administrative Chief, and Company Gunnery Sergeant.
In March 2023, Gunnery Sergeant Velez transferred to Headquarters and Service Battalion, Marine Corps Recruit Depot/Western Recruiting Region (MCRD/WRR), San Diego, California where served as the Battalion Administrative Chief.
In July 2025, Gunnery Sergeant Velez reported to Navy and Marine Corps Appellate Leave Activity (NAMALA) where he is currently serving as the Senior Enlisted Leader.
Gunnery Sergeant Velez' personal awards include Joint Service Commendation Medal, Navy and Marine Corps Commendation Medal (2), Navy and Marine Corps Achievement Medal (3), and Army Achievement Medal.