Michael Flaherty, 28, was last seen in the area of Bankend Road in Dumfries around 9.50pm on Thursday, June 10.
Police Inspector Hayley Little said: “Michael is described as being around six foot tall with brown hair.
"He has an American accent and when last seen was wearing a black jumper, blue jeans and brown 'cowboy' style boots and was in possession of a large red/beige hiking rucksack.”
Anyone with information should contact 101.