Breen has had a long international career which started at the 2008 IAAF World Juniors. The following year she made the final of the 100m at the World University Games. From 2010 until 2016, Mel competed in two Commonwealth Games, two World Championships, two Continental Cups and two Olympics. In February 2014 she broke Melinda Gainsford-Taylor’s nearly 20-year-old national 100m record, running 11.11. In March 2016, she won her fourth national 100m title. After the domestic season, she pursued her Olympic qualifier in Japan, but eventually nailed it in Townsville in June, running 11.31. At her second Olympics in Rio, she placed seventh in her 100m heat. She bypassed the London 2017 World Championships to prepare for a shot at the Gold Coast 2018 Commonwealth Games , which she achieved being named in the Australian team for the 100m and 4 x 100m relay events.
Breen is a cat lover who adopted ‘Cleo’ from the RSPCA in 2015.