You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
The Prime Minister announced the cancellation during her press conference on Omicron today.
Ardern and Gayford, who have daughter Neve, were planning to get married this summer in Gisborne.
"When it comes to events, whether it's a birthday or a wedding or any kind of event of that nature, gathering limits of 100 do come in with the red light setting at 11.59pm tonight," Ardern said.
"It will depend on the nature of the event and if they are using vaccine passes - if they are not, it reduces to 25 people.
"As for mine, my wedding won't be going ahead but I just join many other New Zealanders who have had an experience like that as a result of the pandemic. And to anyone caught up in that scenario, I am so sorry but we are all so resilient and I know we understand we are doing this for one another and it will help us carry on."
The PM was asked how she felt about the cancellation: "Such is life. I am no different to dare I say thousands of other New Zealanders."
Back in December, Ardern was asked about her wedding plans on ZM. "You'd have to ask Clarke, he's in charge," she replied at the time.
"I said to someone I do really think I'm the least-engaged bride. I know the big stuff, but he's really doing the lot."
She said her day was "going to be pretty low key".
In July, Ardern admitted in a radio interview that she won't be embarking on a honeymoon after her big day.
"I guess it's my choice, for having major life events while in this job. So, no one's fault except my own. No complaints from us."
The Herald understands the wedding was to take place at Nick's Head Station near Gisborne and Lorde was rumoured to be performing.
The wedding cancellation may have helped the Prime Minister with her invite dilemmas - the red traffic light setting restricts gatherings to 100 for those who are fully vaccinated.
Ardern previously told Jono and Ben on The Hits that she was struggling to choose which members to include.
"This is actually a real-life dilemma, I have a lot of colleagues," she joked.
Ardern and Gayford got engaged Easter 2019 at Mahia during a break at Gayford's family bach.
He proposed to her at the top of a hill with a diplomatic protection squad officer nearby.
News of the engagement only emerged because a reporter attending a Pike River ceremony saw the Art Deco-style ring on Ardern's left hand and asked Ardern's office about it.
The office later confirmed the news.