The singer-turned-TV presenter joined the ITV1 show in 2000, but told The Mirror that she wants to "move on to new adventures".
She said: "I've had the most amazing ten years since I started doing Loose Women but I wanted to leave on a high.
"During my time on the panel I've had some of the most hilarious moments and outrageous discussions ever - and I've made mates for life... People may be shocked that I decided to leave Loose Women when it is doing so well, winning awards and having great ratings, but I've always wanted to go out on top and that is what I am planning to do."
Nolan added that she would not be leaving the television industry and had "some exciting offers to consider".
ITV's creative director of daytime and lifestyle Fiona Keenaghan said: "We have loved working with Coleen for the past ten years and can't thank her enough for the huge contribution she has made to the success of Loose Women."
> Sarah Millican joins Loose Women panel