Samuel Neilson, 45, was last seen at his home in Stirling at around 1am on Saturday, September 4.
Samuel amassed more than 25 years of service in the armed forces.
He’s described as white, 5ft 8in, of medium build and bald.
Anyone who has information relating to Samuel’s disappearance is asked to contact police via 101 and quote reference 0959 of September 4.