Private Ernesto Delgadillo reported to MCRD, San Diego, CA in January 2004. Upon graduation from recruit training he attended training at Camp Pendleton, CA in May 2004.

Private First Class Delgadillo was transferred to NAS Meridian, MS for training as an Aviation Maintenance Data Specialist. August 2004 he received orders to Miramar, CA joined to VMFA-314, 3D MAW. 
 
In January 2006 and July 2007, Corporal Delgadillo deployed with VMFA-314 Unit Deployment Program participating in multiple coalition and integrated service exercises.
 
In April 2008, Sergeant Delgadillo received orders to Drill Instructor School, San Diego, CA. Sergeant Delgadillo served as a Drill Instructor and Senior Drill Instructor for 3rd Battalion India Co. 
 
In August 2011, Staff Sergeant Delgadillo received orders to HMLA-469, Camp Pendleton, CA. In May 2012 he deployed to Camp Bastion, Afghanistan in support of OEF as the Division Chief. In February 2015 Staff Sergeant Delgadillo was deployed to Okinawa, Japan, in support of the Unit Deployment Program. 
 
In March 2016, Gunnery Sergeant Delgadillo received order to the Naval Safety Center, MARFORCOM, Norfolk, VA. He served as a safety analyst conducting over 200 assessments for all Navy and Marine Corps units. 
 
In May 2019 First Sergeant Delgadillo reported to Marine Detachment Fort Lee, VA as the Alpha Company First Sergeant. During his tour at Fort Lee he managed four school houses (Food Service, Bulk Fuel, Mortuary Affairs, and Air Delivery).  On occasion he filled the role as the Battalion Sergeant Major overseeing all Marine Corps entry level schools aboard Fort Lee. During his tenure at Fort lee he led, mentored, and oversaw the training of over 2,500 students and 100 permanent personnel. 
 
First Sergeant Delgadillo received orders to 2D Battalion, 7th Marines on September 18th, 2021, Marine Air Ground Combat Center Twentynine Palms, Ca assuming duties as Company G First Sergeant. First Sergeant Delgadillo deployed with Company G to Okinawa, Japan in support of the Unit Deployment Program participating in multiple exercises.  He returned from deployment in April 2022 and assumed the role as the acting Sergeant Major for the Battalion.  
 
First Sergeant Delgadillo received orders to 7th Marine Regiment Headquarters in August, 2022 and filled the billet as the Company First Sergeant. He would oversee multiple sections at the Regimental headquarters, accounting for over 400 Marines. 
 
On April 14th, 2023 First Sergeant Delgadillo was frocked to the rank of Sergeant Major and received orders to 2D Battalion, 7th Marines, effective May 1st, 2023. 

Sergeant Major Delgadillo's personal awards include: The Navy and Marine Corps Commendation Medal (w/2 gold stars), Navy and Marine Corps Achievement Medal (w/3 gold stars) and other unit and service awards.
 
Sergeant Major Delgadillo holds a Bachelor Degree in Criminal Justice and currently working on a Master's program.