Great-grandfather Donald Stewart, known as Roy, helped switch on the town's first set of electrical street lamps in Kings Avenue in 1927.
His parents Mr and Mrs William Stewart, along with his sister Jessie also helped run the resort's post office and first telephone exchange in 1915. Mr Stewart, who was shared his life with his late wife Madge, along with a successful career as an electrical engineer has been a long-time supporter of the Conservative Party.
He became a member of Prestatyn Conservative Club in 1930, making him one of the country's longest-serving members of the Tory faithful alive today.
On the eve of his birthday, Mr Stewart, who was joined by family and friends to celebrate his centenary, was contacted by the leader of the opposition, David Cameron, who wished him "health and hapiness for years to come".
Mr Cameron, who was contacted by conservative councillor for Prestatyn East Dr James Davies, said: "I understand that you will be celebrating your 100th birthday on June 13 and I so wanted to take the opportunity both to congratulate you on recahing this terrific milestone and to thank you for your years of support for the Conservative Party.
"I know you joined Prestatyn Conservative Club in 1930 at theage of 21, at a time when you had to be 21 to be able to vote, and so by your birthday you will have been a member of the Conservative Party for over 78 years.
"This really is quaite an achivement and I would like to thank you for your loyal support over so many years."