Sergeant Major O’Connor enlisted in the Marine Corps, and attended Recruit Training at Marine Corps Recruit Depot, Parris Island, South Carolina and assigned to MCCSSS, MCB Camp Lejeune, NC to attend the auto-mechanic course and later transferred to 8th Motor Transport Battalion, 2nd FSSG (Rein) FMFLANT Camp Lejeune, NC as a Heavy Vehicle Operator. PFC O’Connor was then assigned to MCCSSS, MCB Camp Lejeune to attend the Motor Vehicle Operators Course and was transferred to 9th Motor Transport Battalion, FMFPAC, and MCB Camp Butler, Okinawa, Japan. While assigned to 9th Motor Transport Battalion he deployed to Republic of Korea (Pohang, Inchon, and Seoul) as part of Team Spirit, and then transferred to HQ Service Bn MCB MCCDC Quantico, Va as a Motor Vehicle operator.
Sergeant O’Connor reported to Drill Instructor School Marine Corps Recruit Depot Parris Island, SC, for duty as a Drill Instructor with company F, 2nd Recruit Training Battalion where he served as Drill Instructor, Experience Drill Instructor, and Senior Drill Instructor. In April of 1994, he was transferred to HQ MCB Kaneohe Bay, Hawaii for duty as Motor Vehicle Operator. Sergeant O’Connor made a lat move and reported to MATGS NTTC NAS Meridian, MS as a Aircraft Maintenance student. After graduation and earning the MOS 6046, he was transferred to VMFA-212 and VMFA-235 MAG-11 3RD MAW MCAS El Toro, CA and served as the Aircraft Maintenance NCOIC and deployed on a UDP WestPac.
In March of 1998, Staff Sergeant O’Connor reported to Drill Instructor School Marine Corps Recruit Depot Parris Island, SC. After graduation he reported for duty as a Drill Instructor with company C, 1st Recruit Training Battalion. While assigned to company C, 1st Recruit Training Battalion he served as Drill Instructor, Experience Drill Instructor, Senior Drill Instructor, Series Chief Drill Instructor, and Battalion Drill Master. In May of 1999 Staff Sergeant O’Connor was selected to serve on the staff of Drill Instructor School where he served as Basic Warrior Training, Core Value/Instructional Techniques, Physical Training Instructor, Drill Master and Curriculum Developer for 11 classes from 3-99 to 1-02.
In February 2002 Gunnery Sergeant O’Connor was transferred to HMH-464, MAG-29 MCAS New River, Aircraft Maintenance Chief, where he participated in Fire Exercise in Yuma, AZ and deployed on a UDP WestPac. In November of 2002 Gunnery Sergeant O’Connor was transferred to MALS-29, MAG-29 MCAS New River, for duty as the Assistance Production Control Chief and Aircraft Maintenance Admin Chief. Upon his selection to First Sergeant in January 2004, he was transferred to Battery R 5th Battalion, 10th Marines Regiment, 2d Marine Division. First Sergeant O’Connor was part of a Combined Armed Exercise, with Battery R to 3rd Battalion, 12th Marines Regiment 3rd Marine Division during a Unit Deployment Program to Okinawa. Deployed to Yatsubetsu, Japan in support of relocation shoot July 2004 where he served as the Battalion Sergeant Major for 3/12. Deployed to Camp/Mount Fuji(x2), Japan in support of combined arms exercises with Combat Assault Battalion.
In March 2005, First Sergeant O’Connor was transferred to Headquarters Battery and in November 2005 was selected by name to serve with Battery C 1st Battalion 10th Marine Regiment, 2nd MarDiv in direct support of Mojave Viper, then deployed to Al Anbar Province, Iraq in support of OIF III 05-07. First Sergeant O’Connor was transferred to Headquarter Company, Combat Logistic Regiment 27, 2d Marine Logistic Group. First Sergeant O’Connor was transferred to HqCo, Combat Logistic Regiment 2, 2d Marine Logistic Group where he served as the HqCo Regimental First Sergeant and Combat Logistic Regiment 2 Sergeant Major. Sergeant Major O’Connor was promoted to his current rank and was transferred to Marine Corps Recruiting Station Charleston, West Virginia for duty as the Recruiting Station Sergeant Major in March 2008.In April 2011 Sergeant Major O’Connor was transferred to School of Infantry-East, where he served as the Marine Combat Training Battalion Sergeant Major. Sergeant Major O’Connor assumed the duties as the Headquarters and Support Battalion Sergeant Major in December 2012. Sergeant Major O’Connor assumed the duties as the Marine Operational Test and Evaluation Squadron Sergeant Major in October 2013
Sergeant Major O’Connor earned his certifications from International Fitness Association as a personal trainer, his personal decorations include; Meritorious Service Medal, Navy Commendation Medal two gold stars in lieu of third award, Navy Achievement Medal one gold stars in lieu of second award, and Drill Instructor ribbon one bronze star in lieu of second award.