The 29-year-old said she was proud of what she had achieved in the sport.
Coutts, 29, also an eight-time Commonwealth Games champion, said she was proud of what she had achieved in the sport.
"I am really happy. I did the best I could in Rio," she said.
"From a little girl who had a dream to be an elite swimmer, to my final race in Rio I wouldn't change a thing about my career and I am so proud of everything my team and I managed to achieve over the years."
At her second Olympics in London 2012, Coutts joined greats Shane Gould and Ian Thorpe as one of only three Aussie swimmers to win five medals at a single Games.
That added to eight World Championship, six Pan Pacific and nine Commonwealth Games medals -- including eight gold and a silver -- for a total of 28 international medals.
Coutts was dubbed the "Delhi-Golden Girl" after winning five gold medals at the 2010 Commonwealth Games.