Ireland's Harrington has no more 'mountains to climb' after second gold
Harrington said she would be hanging up her gloves after beating Yang Wenlu of China by split decision in the final of the lightweight category.
The 34-year-old became the first Irish boxer to win back-to-back gold medals, adding to her victory from the Tokyo Olympics.
"When you reach a mountain, find a bigger mountain. And that's what I've done. It wasn't easy to climb that mountain," Harrington told reporters.
"It's been three years of madness. It's been hard. So I decided that (this medal) is for me. I'm doing it for me and me alone. And that's what it is. I'm just so happy."
Asked what would come next in her career, Harrington said: "(There are) no more mountains.
"The next chapter is going to be my life chapter, and it's for me and Mandy (wife) now. I just can't wait to live my life.
"Not that I'm not living my life, but to not be looking at the scales every morning. (As a boxer) everything is like, 'Well you can't do that because you might get injured' or 'We can't do that because you'll be tired tomorrow'."
After her win, Harrington delighted the Irish fans that had flocked to Court Philippe-Chatrier to support her with a rousing rendition of "Grace".
"It was absolutely amazing, I said to the coaches after singing, 'Is there anything I won't do?', it was brilliant," Harrington said of her performance.
"The Irish are just great, I never expected anything like that, this is something, I'm never ever going to forget this, ever."