The Beijing 2008 100m hurdles gold medallist gave birth to a baby girl, named Harper, in April having quit the track in September 2018.
But the 35-year-old from East St. Louis, Illinois announced her comeback to her local TV station KSDK News and signalled her ambition to bid for a third Olympic medal at Tokyo 2020.
"I just think about crossing that line and then getting Harper handed to me and it's going to be like, "Waaaah, we did it! I know it's going to be so exciting." - Dawn Harper-Nelson talking to KSDK News
A decade at the top
At 24, Harper claimed a surprise gold in the 100m hurdles at Beijing 2008, crossing the line first after team-mate Lolo Jones had clattered the penultimate hurdle with the title at her mercy.
Having struggled to gain sponsorship ahead of the Games, she wore spikes given to her by injured two-time world champion Michelle Perry.
Injuries marred Harper's next couple of seasons before she took bronze at the 2011 World Championships in Daegu.
And she put up a strong defence of her Olympic title at London 2012, beating the previous Olympic record with a new personal best of 12.37s but having to settle for second behind Australia's Sally Pearson.
After marrying Alonzo Nelson in 2013, Harper-Nelson just missed out on the medals at the World Championships although she did claim her second Diamond League title.
She was ranked number one in the world in 2014 but, after winning her fourth national title to qualify for the 2015 World Championships, suffered disappointment in Beijing as she crashed out in the semi-finals.
2016 saw another setback as Harper-Nelson missed out on qualification for Rio 2016 by just one-hundredth of a second.
But she was back to something like her best in 2017, taking silver behind Pearson again in London's Olympic Stadium in the final of the World Championships.
Retirement and return
Harper-Nelson announced in April 2018 that it would be her last season, telling Reuters, "Since I was a child, there were always three things I wanted: To be an Olympic gold medalist, a wife and a mom.
"Right now I am two for three and I’m feeling the urge to be someone’s mom."
A second place in the Monaco Diamond League was her best finish in a disappointing campaign, but she announced her pregnancy in style with this video last November.
And Harper-Nelson completed her set of life goals in April when she gave birth to Harper.
But she told KSDK News that she wants to return to competition to set an example to her daughter having previously thought that motherhood and competition did not mix.
Harper-Nelson said, "I always thought that I had to completely stop running to be a mother. That was just what I told myself, I had made that up in my own mind.
"I almost don't want her to feel like her birth symbolised Mom stopping everything, like all of her dreams. That to me did not fit well at all.
"I want to be a mom that shows her an example of, 'You can do whatever you put your mind to'.
Now she wants to qualify for a third Olympic Games at Tokyo 2020 and doesn't have to look far for inspiration.
"This new Dawn's body, we're gonna kick butt. We're gonna make the adjustments that I need to do and we'll be OK." - Dawn Harper Nelson talking to KSDK News