In March 2010, Jenneke finished first in the 100 m hurdles, breaking the national record in the women’s sprint medley relay at the 2010 Australian Junior Championships. She competed in the 2011 Pirtek Athletic Allstars event. In July of that year, she was on Australia’s team at the 2010 Singapore Youth Olympic Games, running the 100 m hurdles and the women’s medley relay. In the hurdles, she came second with a time of 13.46 and set a personal best after winning her heat, and the medley relay team came fourth. Her medal was the first Australia won at the Games in athletics.

In 2011, Jenneke competed at the New Zealand hosted Cooks Classic. At the 2011 Australian Junior Championships, she had a first-place hurdles finish in the under-20 group. In April 2011 she competed at the 89th Australian Athletics Championships and finished third in the 100 m hurdles behind world champion Sally Pearson.

On 15 July 2012, Jenneke finished fifth in the 2012 IAAF World Junior Championships 100 m hurdles. After the competition, a video of her 100 m hurdles taken during the heats race, was subsequently posted on a video-sharing site, raising her profile around the world.

In July 2012 videos of Jenneke dancing during her pre-race warmup before the 100 m hurdles race at the 2012 World Junior Championships in Athletics in Barcelona went viral on YouTube. One clip received 19 million views by the following week and was featured on the American late-night talk show, The Tonight Show.

In January 2013 Jenneke was ranked tenth on AskMen.com’s 99 Most Desirable Women 2013. She was featured in the 2013 Sports Illustrated Swimsuit Issue.

Jenneke acted in a short comedic video produced by the website The Chive titled Forever Alone Meets Michelle Jenneke, playing herself in a piece referencing her viral video. The video had received over 10 million views on YouTube by 2014.

In 2014 Jenneke was featured in a video-heavy mobile computing app on stretching techniques called Stretch with Michelle Jenneke. Early the same year, she was a star in the Top Gear Sydney Festival, racing a Nissan GT-R.

Jenneke’s personal best is 12.82 set at the Australian Athletics Championships in Brisbane on 29 March 2015. She finished second at nationals to qualify for the 2015 World Championships in Beijing. Jenneke got through the heats to make the semi-finals. She finished sixth in her semi and in 18th place overall.

In March 2016, Jenneke represented Australia at the World Indoor Championships in Portland, Oregon and finished 10th. The next month she won the Australian National Championship 100 m hurdles final with a time of 12.93, qualifying her for the 2016 Summer Olympics in Rio de Janeiro. In August, Jenneke competed in the Olympics but was unable to get out of the heats, finishing in sixth with a time of 13.26. She would have needed a near personal best to qualify as the third qualifying time in her heat was 12.85. Australian head coach Craig Hilliard was critical of her performance.

In August 2017, Jenneke competed in her second World Championships and got through the heats to the semi-finals, finishing in 7th with a time of 13.250. She would have needed a near personal best to reach the final as the second qualifying time in her semi was 12.85. In the BBC’s montage of events (the moments of the games as BBC presenter Gabby Logan called it) on the games’ final evening Jenneke and her warm up jig was featured.

In April 2018, she represented Australia at the Commonwealth Games, finishing fourth at 13.07, after running a qualifying time of 12.99.