Ko, 27, went into her final round at Le Golf National on Saturday in first-equal with Switzerland’s Morgane Métraux, but quickly took outright first position as Métraux stalled.
After a series of birdies and par shots throughout the first half of the course, Ko sat at 11-under, with a whopping five-point lead over her closest rivals.
The only major upset came on the 13th hole, when she sent a shot into the water, leading to a double bogey.
That decreased her lead to three points and her score to nine-under.
Birdies from Germany’s Esther Henseleit saw her decrease Ko’s lead to two, then just one, but Ko hung on to make par with some long shots on the final few holes.
A birdie on the 18th saw her increase her lead to two shots and her score to 10-under, to claim the gold.
New Zealand’s Lydia Ko competes during round 4 of the women’s golf individual stroke play of the Paris 2024 Olympic Games at Le Golf National in Guyancourt, south-west of Paris, on August 10, 2024.
Henseleit took silver at eight-under, while China’s Lin Xiyu took the bronze at seven-under.
Ko already held a silver medal from the 2016 Rio Olympics and a bronze from Tokyo 2020.
The gold medal win means she now has enough points to be inducted into the LPGA Hall of Fame, becoming its 35th living member.
She will not be automatically inducted and instead must be voted in.
It was New Zealand’s eighth gold of the Paris Games and its 17th medal overall.
Earlier this week, Ko told RNZ she had “nothing to lose” heading into the final round.
“It’s pretty cool that all three of the Olympics that I played in, I’m in the final group for all three of them. I actually didn’t think of that until a couple of days ago. It’s kind of like a bucket list that has been checked,” she said.
“Because I have two medals under my belt, I kind of feel like I’ve got nothing to lose. I know that I’m going to give it my all, and I’m going to try my 100 percent.
“If it’s meant to happen, it’s going to happen.”
