Muldowney, who attended the Royal Military Academy Sandhurst, joined the Army in January 2020 and was commissioned into the Royal Artillery in December of that year.
He served in multiple roles and was deployed in November 2021 to Estonia for six months.
He had been seriously injured on a commando course in January 2025 and ordered to pause and rehabilitate, but returned to duty after his recovery.
Tributes were made by military personnel who had served with him, describing him as a “true friend” and a “truly kind person”.
Known as Gilbert, he was “an immensely enthusiastic officer who embraced life with a vigour that inspired everyone around him”, Commanding Officer of the 4th Regiment Royal Artillery, Lieutenant Colonel Henry Waller, said.
“Always full of ideas and never without a bright smile, Gilbert approached every challenge wholeheartedly, whether in camp or out in the field.”
Waller described Muldowney as an “outstanding officer who consistently put his soldiers first”, calling him “a rising star” in the Army and the regiment.
He will be remembered “for his easy-going nature, boundless energy, and infectious sense of humour”.
Captain Duncan Morrison, who met Muldowney in 2021, said his friend “lived life to the fullest and made lasting connections with everyone he met”.
Captain Helen Brackenbury said Muldowney served all those under his command authentically, adding “everyday he displayed a level of spirit I continue to be in awe of”.
Major Martin Simms called Muldowney “an absolute credit to his family and his friends”, saying “we are devastated by the loss”.
“Gilbert’s loss is felt deeply by his unit, his peers and all who had the privilege of serving and spending time with him,” Captain Ross Beeby also said.