John Hamlyn, 81, was first elected mayor of Crow Head in 1963. The community, with a population of 250, sits just north of Twillingate.
The title of longest-serving mayor is tough to prove, because each province is responsible for keeping its own records.
Mississauga, Ont., Mayor Hazel McCallion, 92, often gets credit for the title, but has only served 34 years as mayor of the city.
Hamlyn said he may not have official recognition, but he feels pretty certain that he's the longest-serving mayor in Canada.
"I started when I was quite young," Hamlyn said. "It's just something that you thought, in those early days, maybe you had some extra time you could serve your community, and serve the people well.
"It started out to be a one term, and naturally, you enjoy it."
He said he doesn't have any plans of retiring any time soon, either.
"I feel as young today as I did 50 years ago, and that's the truth," Hamlyn said.
Hamlyn said he has plans to run for another four-year term.