Tiger Command Sergeant Major

CSM O'Brien

Command Sergeant Major Seann P. O’Brien is a native of Miami, Florida.  He entered the United States Army on January 26, 1989 and completed Armor Crewman One Station Unit Training (OSUT) at Fort Knox, Kentucky.


Command Sergeant Major O’Brien has served in every leadership position in the Armor from Tank Gunner, Tank Commander, Section Sergeant, Armor Platoon Sergeant, First Sergeant, and Command Sergeant Major. His assignments include: Armor Crewman, 1st Squadron, 3rd Armored Cavalry Regiment, Fort Bliss, Texas; Tank Gunner and Tank Commander, 3-64 Armor Battalion and 2-64 Armor Battalion, 3rd Infantry Division, Schweinfurt, Germany; 1-77 Armor Battalion, 1st Infantry Division, Schweinfurt, Germany; Training Developer/Writer, United States Army Armor Center, Fort Knox, Kentucky; Operations Sergeant and Squadron Master Gunner, 2nd Squadron, 16th Cavalry, Fort Knox, Kentucky; Platoon Sergeant, 1-67 Armor Battalion, 4th Infantry Division (M), Fort Hood, Texas; Armor Platoon Observer/Controller, Combat Maneuver Training Center, Hohenfels, Germany; First Sergeant, 2-81 Armor Battalion, 1st Armor Training Brigade, Fort Knox, Kentucky; First Sergeant, HHT 1st Squadron, 3rd Armored Cavalry Regiment, Fort Hood, Texas where he deployed to Iraq in support of OIF 07-09; Command Sergeant Major for the Grizzly Observer/Controller-Trainer Team, Joint Multinational readiness Center, Hohenfels, Germany. Command Sergeant Major for 1st BN, 4th IN REGT (SEP)(OPFOR), Joint Multinational Readiness Center, Hohenfels, Germany.


Command Sergeant Major O’Brien’s military and civilian education includes: Primary Leadership Development Course (Commandant’s List), Basic Noncommissioned Officer Course, Advanced Noncommissioned Officer Course (Commandant’s List), First Sergeant Course (Commandant’s List), M1/M1A1 Abrams Master Gunner Course, M1A2 Tank Commander Certification Course, National Training Center and Joint Multinational Readiness Center Observer/Controller Academy, Combatives Level 1 and 2, and a graduate of the United States Army Sergeant Major Academy (Commandant’s List) class 59. Command Sergeant Major O’Brien has earned a Bachelor’s Degree in Science from Excelsior University.


Command Sergeant Major O’Brien’s military awards and decorations include: the Bronze Star Medal, Meritorious Service Medal (5th Award), Army Commendation Medal (2nd Award), Army Achievement Medal (9th Award), Army Good Conduct Medal (7th Award), National Defense Service Medal (2nd Award), Iraq Campaign Medal, Global War on Terrorism Service Medal, Noncommissioned Officer Professional Development Ribbon (w/numeral 4), Military Outstanding Volunteer Service Medal, Army Service Ribbon, Overseas Service Ribbon (w/numeral 4), Army Superior Unit Award (2nd Award), and the German Schutzenschnur (Silver Badge). Command Sergeant Major O’Brien is also a member of the Order of Saint George (Bronze Medallion) and the Order of Saint Maurice (Legionnaire)