It is understood the 59-year-old went walking in The Gap of Dunloe
Gardaí are appealing for assistance in tracing the whereabouts of 59-year-old Gilbert Fitzpatrick.
Mr Fitzpatrick, who is from Navan in Co Meath, went missing while on holiday in Tralee.
He was last seen at 11.00am on Saturday June 9th when he travelled to Killarney.
It is understood he went walking in The Gap of Dunloe area on that day.
The alarm was raised when he failed to return to his accommodation in Tralee the following day.
Mr Fitzpatrick is approximately 5ft 5' in height, of slight build with dark/grey hair.
When last seen he was wearing a light blue check short-sleeved shirt, navy trousers and black shoes.
He was also carrying a rain jacket.
Gardaí are appealing to anyone who may have seen him to contact Tralee garda station at 066-710-2300, Killarney station on 064-6671160 or the Garda Confidential Line 1800-666-111.