The executive board of Unesco endorsed the nomination during its latest session earlier this week.
There are only 19 others given the same status in the southern hemisphere and New Zealand is now one of just 48 countries in the world that has a designated geopark.
The Waitaki Whitestone Geopark covers an area of over 7000sq km and has many different sites across the district including limestone cliffs, glacial valleys and ancient marine fossils.
The designation had been "a long time coming", Waitaki Whitestone Geopark manager Lisa Heinz said.
"Particularly with Covid, there’s been a bit of a delay and a lot of hard work going into it. It feels really great.".
They submitted the application to Unesco in 2019.
The pandemic delayed the process for two years but it was was restarted last year with an evaluation mission in July, after which the Unesco council recommended the application be accepted.
It was "so exciting" that the designation was now officially official, Waitaki Whitestone Geopark Trust chair Helen Jansen said.
"It’s an absolute relief to know that it’s confirmed.
"We’ve been assured for so long, but now it’s confirmed," she said.
Now that it had the Unesco designation, the geopark could be an "eye opener" for New Zealanders who may not have been aware of what a geopark even was, Waitaki Whitestone Geopark Trust advisory trustee Mike Gray said.
"I’ve been to a couple of geoparks in the UK so I’m aware of them but a lot of New Zealanders aren’t.
"So we’re bringing the concept of a geopark down to the southern hemisphere, that’s the big thing.
"It’s likely to be an attraction to overseas people who know what geoparks are."
Waitaki Mayor Gary Kircher said he hoped that the designation was just the beginning of what the geopark could accomplish.
While an invite-only ceremony to celebrate the designation will be held in Oamaru next week, there are plans for a series of events held in October for the the public to partake in.
