1st Sergeant Denning is a native of Simi Valley, California. He reported to MCRD San Diego for Recruit training in June of 2005. Private Denning graduated recruit training in September of 2005, was selected as the company honor man and meritoriously promoted to the rank of Private First Class.
Private First Class Denning completed Infantry training aboard School of Infantry West. Private First Class Denning reported to Alpha Company, 1st Battalion, 5th Marine Regiment in Camp Pendleton, California. There he served as a machine gunner, machine gun team leader, and machine gun section leader. In June of 2006 he was promoted to the rank of Lance Corporal. From July 2006 to January 2007, he deployed to Okinawa Japan as a machine gun team leader with the 31st Marine Expeditionary Unit. In November 2007 he was meritoriously promoted to the rank of Corporal. From November 2007 to May 2008, he deployed with the 11th Marine Expeditionary Unit where he served as a machinegun section leader. On March 2nd, 2009 he was meritoriously promoted to the rank of Sergeant. From June 2009 to December 2009, Sergeant Denning deployed to Nawa, Helmand Province, Afghanistan where he served as a rifle squad leader during Operation Enduring Freedom. From March 2011 to October 2011, he deployed to Sangin District, Helmand Province, Afghanistan as an Embedded Training Senior Enlisted Advisor partnered with 1st Tolay, 2d Kandak, 2d Brigade, 215th Corps, in support of Operation Enduring Freedom.
In June 2012, Sergeant Denning reported to the School of Infantry-West where he was assigned to Infantry Training Battalion, Bravo Company as the lead company infantry machinegun instructor. In June 2013, he was assigned to Headquarters and Instructor Company, where he served as the Chief Instructor for Infantry Machinegunners Course.
In June of 2015, Sergeant Denning separated from the active duty component and reported to Weapons Company, 2nd Battalion, 23rd Marine Regiment, where he served as the Combined Anti-Armor Team Platoon Sergeant. In April of 2016 he was promoted to the rank of Staff Sergeant. From November 2016 to March 2018 Staff Sergeant Denning served as the acting Combined Anti-Armor Team Platoon Commander.
In May 2018, Staff Sergeant Denning was assigned as the Combined Anti-Armor Team Platoon Sergeant for the Battalion’s activation and deployment to Okinawa, Japan from September 2018 to March 2019.
Gunnery Sergeant Denning served as the Operations Chief for Weapons Company, 2/23 from July 2021 to September 2023. Gunnery Sergeant Denning then served as the Company Gunnery Sergeant for H&S company 2/23 from October 2023 to October 2024.
In October 2024, Gunnery Sergeant Denning was promoted to the rank of 1st Sergeant and is currently assigned to Company G, 2/23.
His personal awards include the Bronze Star Medal with combat distinguishing device, The Purple Heart Medal, The Naval Achievement Medal with combat distinguishing device with three gold stars, and the Combat Action Ribbon.