Samuel Townsley (28) was last seen in Paisley on Monday, October 17, and was reported missing on Thursday (January 26).
He is about 5ft 3ins, stockily built, and has very short brown hair,
Inspector Christine Boyd of Irvine Police Office said: “It is not unusual for him to go off by himself for weeks at a time and not maintain contact with his family or friends.
“His family has contacted police as they haven’t heard from him since October, and are becoming increasingly concerned for his safety and wellbeing.
“We are appealing to anyone with information on Samuel’s whereabouts to contact us, and we would also appeal to Samuel himself to make contact with police to let us know he is safe and well.”
Anyone with information should contact Police Scotland through 101.