The 17-year-old tees off tonight (NZT) at the Evian Championship in France, the year's final major, in an attempt to break one of the oldest records in golf.
It's 146 years since Young Tom Morris upset his father to win the Open Championship in 1868 and become the youngest major winner in history, at the age of 17 years, five months and eight days.
Ko will also become the world No 1 with a win and she takes plenty of confidence into her record-breaking bid after finishing runner-up in last year's event. She has fond memories of that performance, which proved an important week in her career.
"This was the last tournament I played as an amateur," Ko said. "I got a lot of confidence coming off the Canadian Women's Open and then playing well here, so I think that just gave confidence in my game and I kind of felt that maybe I was ready to turn pro."
That happened a month later and Ko's transition to the professional ranks was an immediate success. She took her first title the LPGA Swinging Skirts in Taiwan in only her second start, since winning two more times in her rookie season on the LPGA Tour.
Ko has recently had two weeks away from golf after the Canadian Open -- one of the longest breaks of her young career -- and it was just what she needed.
"I pretty much chilled out at home," she said. "I just tried to be a normal teenager -- had some fatty food. That's not what the normal athlete would be. But I just enjoyed not touching my clubs and not having to worry about what else was going on.
"During that whole time I really did nothing. I probably gained some weight, too, but to have a week off during the season, that's not what I would have planned, but I think it was a good time for me."
It was also good for her ailing wrist. Ko has had to manage the pain in recent time but she said the injury is feeling a lot better.
"I haven't been worrying about it, which is really good because the game itself is pretty tough and there are other things I need to worry about. My wrist is feeling good and I think I'm feeling good. So hopefully I'm prepared for what's coming."
Ko said the challenge at the Evian Resort Golf Club is different to what she remembers, as the course has more run and many of the tee positions have been pushed forward.
"But I think the course is great. There are definitely tough holes out there, but at the same time there are some opportunities for us to make some birdies."
Ko will tee off at 6:40pm (NZT) alongside defending champion Suzann Pettersen of Norway and American Lexi Thompson.
APNZ ks lb
