The 35-year-old, who gave birth to son Ethan at the end of October last year, had hoped to return for the Commonwealth Games in Glasgow, but has now opted to hang up her spikes.
McConnell said in a statement: "When I fell pregnant with Ethan I made the decision to continue with training through and post pregnancy and see where that took me. I have now reached the decision that my career as a professional athlete has come to an end.
"I was always a working athlete and will continue as a working mum, focusing on the media and other work that has always sat as part of my double career track alongside athletics.
"2014 is obviously a huge year for Scotland and this was not an easy decision to make as it means not competing in a home Commonwealth Games.
"Now is my time however. I am excited for the new opportunities and challenges that retiring from athletics will bring me and look forward to getting involved with a home games - just not as a competing athlete."
McConnell has won more major championship medals than any other Scottish athlete with nine, including Commonwealth silver in 2002 and two World Champion relay bronzes.