Is there any record of who received the last battlefield commission in the U.S. military (in any service)?

I am not going to bet the farm on this one, but Vietnam would seem to be the one I would go with. As to who...IDK.

RESEARCH!! In thirty seconds I found Who was the last person to receive a battlefield commission in the US Army? Not an enlisted promotion, but a promotion from enlisted to officer.
I believe the last official one was during Vietnam, but I don’t have the person’s name.

Since then, I haven’t heard of any but one, and that was a rather unique situation outside of combat.

It happened at Fort Benning some time before 1984, as I only met the man in his role as a commanding officer of 51st Company, Officer Candidate School (this was prior to their current designations of A-B-etc. - it was 50th and 51st Company). The man was Michael (‘Iron Mike’) Wagers, who was a direct commission from First Sergeant to Captain.

I had a cousin by the name of Baker who received a battlefield commission. He retired as a Major from the Army stationed at 5th Army HQ, either in Chicago or Fort Sheridan, IL, sometime in mid 50s

Not sure if this qualifies. Not much out there. Maybe US Army Historical folks. I believe Maj Wagers resides in TN, and was inducted into Ranger HOF in 2018. https://www.quora.com/Who-was-the-last-person-to-receive-a-battlefield-commission-in-the-US-Army-Not-an-enlisted-promotion-but-a-promotion-from-enlisted-to-officer

The info must be somewhere.

That's a great question. I'm sure there is, and it would make an interesting story.

The last one I know of happened in 1980

https://www.benning.army.mil/Infantry/ARTB/RHOF/index.html

From Ranger hall of Fame...

Major Michael R. Wagers is inducted into the Ranger Hall of Fame for his service and embodiment of the Ranger Creed throughout his military career. As a 19-year old Staff Sergeant, MAJ Wagers served as a Squad Leader Platoon Sergeant and Platoon Leader of a Rifle Platoon in Vietnam. Of particular significance, the entire year he was leading his platoon, there was only one member who did not return from Vietnam alive. He earned his Ranger Tab in Ranger Class 13-71, and was always eager to hone his skills. The Provo, Utah native went on to complete Pathfinder School, Jumpmaster School, 3rd Army Chemical-Biological-Radiological Warfare School, 3rd Army Noncommissioned Officer Academy, and was also selected to attend The Canadian Winter Warfare Instructor Course. He was assigned as a Rifle Platoon Sergeant with Company C (Rangers), 1st Battalion, 29th Infantry and a year later was to be the youngest of the original nine Rifle Platoon Sergeants for the newly formed 1st Ranger Battalion, 75th Infantry. In 1980, after only thirteen years' service, First Sergeant Wagers made a career status change; he received an Honorable Discharge with a concurrent call to active duty (Direct Commission) as a First Lieutenant, Infantry, assigned to the 21st Infantry, 25th Infantry Division. In 1984, after the activation of the 75th Ranger Regiment, General Wayne A. Downing, having first-hand knowledge of Major Wagers abilities as a leader and trainer, asked Major Wagers to serve as the first Commander of the Ranger Indoctrination (RIP) Detachment, 75th Ranger Regiment, this marking his third consecutive command and his fourth Ranger assignment. Most recently, he has continued to share his knowledge gleaned throughout his career while traveling to Saudi Arabia and the Middle East, where he lived and worked as a consultant for a total of eighteen years. He now resides with his wife in Tennessee and is active with other Rangers of Middle Tennessee and enjoys spending time with, and mentoring and life coaching, young Rangers and other veterans.

There was at least one from 173rd LRRP/N Rangers but it was a direct commission, i.e. he was recommended to and approved by higher command, a records check was made, and he went before a board of officers. These were rare and I do not think the “battlefield commission” occurred in RVN as in “sergeant, take command of your platoon, you are a lieutenant”