Police Scotland say they received a number of reports around 10.50 am from passing travellers concerned about his welfare.
The man, described as wearing a tweed jacket and a flat cap, was walking south in the Kirkpatrick Fleming area.
A spokesman said they were keen to ensure the man was OK and were asking for the public or the walker himself to get in touch.
Anyone who can help is asked to use the non-emergency 101 number and contact Lockerbie Police Station.
NEWSDESK: 01461-202417