Command Sergeant Major Robert Haynie entered the Army in July 1994 and was assigned to Fort Drum, NY, in the 3rd Battalion, 14th Infantry and later assigned to 4th Battalion, 31st Infantry as a Scout and Scout Team Leader.

In 1997, he was assigned to 2nd Battalion, 75th Ranger Regiment where he performed duties as a Team Leader through Anti-Tank Section Leader and Headquarters Platoon Sergeant.

In 2002, he was assigned to Headquarters, I CORPS, Fort Lewis, WA,
as the G3 Air NCOIC until he returned to 2nd Battalion, 75th Ranger Regiment as a Rifle Platoon Sergeant in 2003.

In 2006 he was assigned to 75th Ranger Regiment Headquarters and initiated the Ranger Dog Program and served as the program manager. He was then assigned to 1st Battalion, 75th Ranger Regiment, serving as First Sergeant for Alpha Company and Headquarters Company.

Upon completion of the United States Army Sergeant Major Academy, he returned to the 75th Ranger Regiment serving as the Regimental Deputy Operations Sergeant Major and Regimental Special Troops Battalion Operations Sergeant Major, before assuming responsibility of the RSTB. He assumed responsibility of the 198th Infantry Brigade June 2016 and served as the Brigade CSM until November 2017. He was then assigned to the 177th Armor Brigade December 2017 and served as the Brigade CSM until July 2019.  He then served as the SGM for the Office of the Secretary of Defense Close Combat Lethality Task Force until March 2020. Currently SGM Haynie serves as the Army Talent Management Task Force, NCO initiates Team Lead. 

SGM Haynie has deployed 11 times in support of the Global War on Terror. His military education includes: the U.S. Army Airborne School, Ranger School, Jumpmaster Course, Battle Staff Course, Master Fitness Course, SERE-C, Combat Diver Qualification Course, and the Joint Basic Military Freefall Course.

SGM Haynie’s awards and decorations include the Combat and Expert Infantryman's Badges, Master Parachutist Badge, Combat Diver Badge, Military Freefall Badge, and the Ranger Tab. His awards include the Legion of Merit with oak leaf cluster, the Bronze Star Medal with oak leaf cluster, Purple Heart, the Defense Meritorious Service Medal, Meritorious Service Medal with two oak leaf clusters, Joint Service Commendation Medal, Army Commendation Medal with "V" device and two oak leaf clusters, Army Achievement Medal with three oak leaf clusters, Presidential Unit Citation, Joint Meritorious Unit Award, Valorous Unit Award with oak leaf cluster, and the Army Good Conduct Medal sixth award.

He has a bachelor's degree in Business Management from Excelsior College. SGM Haynie is married to the former Cyndi Miller from Akin, South Carolina, and they have two sons: Trenton and Trebor.