Henry Thayer, 98, was joined by family and fellow brethren of Freemasons New Zealand at the Masonic Lodge in Wānaka, where he was presented with his 80-year bar.
Speaking before the ceremony, Freemasons New Zealand Grand Master James Watt said members had travelled from across the country to celebrate Mr Thayer’s achievement.
"An 80-year bar is unique... so unique it’s the first."
Mr Watt said Mr Thayer’s commitment to the society throughout his 80 years of membership only underlined the importance of the occasion.
"He’s a very active member, highly respected."
Mr Thayer was also presented with a framed certificate and a fruitcake with icing that bore the Freemasons’ square and compass symbol.
Mr Thayer said the ceremony was a "very humbling" experience.
"I’ve enjoyed the Masonry. I got a lot out of it."
Mr Thayer joined the Freemasons in 1943 at the age of 18, the youngest eligible age for a member.
Prior to moving to Wānaka in 1990, he had owned a family farm in Waikaka alongside his wife and three children.
Son Myles Thayer said the family appreciated being able to celebrate the occasion with their father, and recognise what had always been an important element of his life.
"You know, when you get to his age, all your old friends, they’re not here any more.
"So it’s good to be a member of a group. They’ve been very supportive of him as well."
While society membership was down from historic highs in the post-WW2 era, younger generations were now showing an interest, Mr Watt said.
"And that’s because they’re looking for something in their life which is not as material, not as focused on themselves."