Sergeant Major David Sanchez was born on 26 August 1979 in Rosenberg, Texas, and graduated from B.F. Terry High School in 1998. He enlisted in the United States Marine Corps on 28 October 2002, attended Recruit Training at Marine Corps Recruit Depot (MCRD) San Diego, California, and was meritoriously promoted to Private First Class on 2 February 2003. Sergeant Major Sanchez attended Marine Combat Training at Camp Pendleton, California, and then reported to Assault Amphibian School, Camp Pendleton, where he earned the MOS 1833.
In May 2003, Sergeant Major Sanchez received orders to 3D Assault Amphibian Battalion, Camp Pendleton. While assigned to this command, he served as an Assault Amphibian Vehicle Crew Chief, Assistant Section Leader, and Section Leader. He was promoted to Lance Corporal on 1 October 2003. In February 2004, Sergeant Major Sanchez deployed with Company A in support of Operation Iraqi Freedom II, where he participated in Operation Reaper Sweep in Fallujah, Iraq. He was promoted to Corporal on 1 August 2004. In July 2005, Sergeant Major Sanchez deployed with Company E, 1st Platoon, as part of the 13th Marine Expeditionary Unit in support of Battalion Landing Team 2/1. While deployed, he participated in multiple operations, including Operation Iraqi Freedom and Operations Steel Curtain and Bright Star in Alexandria, Egypt. He was promoted to the rank of Sergeant on 1 November 2005 and to Staff Sergeant on 1 January 2010. In May 2010, Sergeant Major Sanchez deployed with Company E, 1st Platoon, as part of the 15th Marine Expeditionary Unit in support of Battalion Landing Team 1/4. While deployed, he participated in bilateral training with the Korps Marinir (KORMAR) in Java, Indonesia, and with the Jordanian Operational Program in Amman, Jordan.
In July 2011, Sergeant Major Sanchez received orders to the Basic Recruiter Course (BRC) in San Diego, California. He successfully completed BRC 1-12 on 15 December 2011 and received orders to 8th Marine Corps District, Recruiting Station Houston, Recruiting Substation Westheimer, where he served as a Canvassing Recruiter until August 2012. Within the first six months on recruiting duty, Sergeant Major Sanchez was selected to become the Staff Noncommissioned Officer-in-Charge (SNCOIC) of a Recruiting Substation. On 1 November 2012, he was assigned to RSS Pearland, Recruiting Station Houston, where he served as the SNCOIC until December 2014. Sergeant Major Sanchez was meritoriously promoted to the rank of Gunnery Sergeant on 2 July 2014. On 1 January 2015, he was assigned to RSS Memorial City, Recruiting Station Houston, where he served until December 2015. In January 2016, he assumed the responsibilities of the Military Entrance Processing Station (MEPS) Service Liaison. In January 2017, Sergeant Major Sanchez received orders to 8th Marine Corps District, Recruiting Station Fort Worth, where he served as the Assistant Recruiter Instructor.
On 28 February 2019, Sergeant Major Sanchez was promoted to First Sergeant and received orders to 5th Battalion, 11th Marines, where he served as the Battery R First Sergeant. On 6 June 2021, he received orders to Marine Wing Support Squadron 372, where he served as the H&S Company First Sergeant, Support Company First Sergeant, and Squadron Sergeant Major. On 12 January 2023, Sergeant Major Sanchez was promoted to his current rank and served as the Recruiting Station Sergeant Major for Recruiting Station Twin Cities, Minnesota, 9th Marine Corps District. On 4 December 2025 he received orders to 2nd Battalion, 1st Marine Regiment and is presently serving as the Battalion Sergeant Major.
Sergeant Major Sanchez's personal decorations include the Meritorious Service Medal, Navy Commendation Medal (x4), Navy and Marine Corps Achievement Medal, Combat Action Ribbon, Navy Unit Commendation, Navy Meritorious Unit Commendation (x4), Marine Corps Good Conduct Medal (x6), Iraq Campaign Medal (x3), Global War on Terrorism Expeditionary Medal, Global War on Terrorism Service Medal, and Sea Service Deployment Ribbon (x4).