Sergeant Major Roberto E. Diaz was born in Great Lake, Illinois on May 14, 1985. He enlisted in the United States Marine Corps in July 2002, and completed recruit training at MCRD San Diego, California in September 2003.
In December 2003, Private First-Class Diaz reported to First Light Armored Reconnaissance Battalion, First Marine Division, Camp Pendleton, C.A., where he served as a Supply Administration Clerk.
Lance Corporal Diaz deployed to Iraq in support of Operation Iraqi Freedom twice in during 2004-2006. In June of 2006, Corporal Diaz was promoted to the rank of Sergeant.
In May 2007, Sergeant Diaz left active duty to pursue educational opportunities outside of the Marine Corps, and in July 2009, affiliated the United States Marine Corps Reserve and attached to Marine Air Control Group 48, Fourth Marine Air Wing, Great Lakes, Illinois, where he served as Supply Platoon Staff Noncommissioned Officer in Charge. In March 2010, Sergeant Diaz was promoted to the rank of Staff Sergeant.
In March 2014, Staff Sergeant Diaz was promoted to the rank of Gunnery Sergeant. In June 2014, Gunnery Sergeant Diaz reported to Marine Wing Support Squadron 471, Marine Air Control Group 47, Fourth Marine Air Wing, Minneapolis, Minnesota. At MWSS-471, Gunnery Sergeant Diaz held numerous billets including, Supply Staff Noncommissioned Officer in Charge, Logistics Chief, Training Chief, Headquarters and Service Company First Sergeant, and Squadron Gunnery Sergeant.
In July 2019, Gunnery Sergeant Diaz returned to Marine Air Control Group 48, Fourth Marine Air Wing, Great Lakes, Illinois, where he served as Supply Staff Noncommissioned Officer in Charge. In June 2020, Gunnery Sergeant Diaz was promoted to the rank of First Sergeant and completed two successful assignments as a First Sergeant with 2nd Battalion, 24th Marines, and Headquarters Battery, 14th Marines.
In November 2024, First Sergeant Diaz was frocked to his present rank and reported to 4th Assault Amphibian Battalion in Tampa, Florida, where he currently serves as the Command Senior Enlisted Leader.
Sergeant Major Diaz’s accolades include a bachelor’s degree in business administration from DePaul University, and a master’s degree in business administration from Northeastern Illinois University. His personal decorations include the Navy and Marine Corps Commendation Medal, gold star in lieu of second award, Navy and Marine Achievement Medal, and the Armed Forces Reserve Medal with a bronze hourglass. Outside of the Marine Corps, Sergeant Major Diaz serves as the Chief Operations Officer within the City of Chicago’s Department of Aviation.