The 36-year-old first rose to prominence in 1998 when he won the British junior road race title. After being part of the British development programme, Barker went to live in France to gain experience of racing on the continent.
Barker briefly retired in the mid-2000s, but returned to racing in 2010 and has since become a regular fixture on the British scene, winning the British Cycling road series overall in 2014.
“I’ve been a full time professional cyclist since I was 16 leaving college to pursue my dream,” said Barker in his retirement statement.
“Cycling has offered an opportunity for me to see the world, meet many special people and most importantly it has been a way for me to get the best out of myself through my drive and ambition to achieve results.
“As my career developed so did my objectives moving to a more senior mentor type role in the teams I rode for later in my career. I’ve always enjoyed sharing my experience with younger riders and that has been a central role this year with One Pro Cycling.”
Watch: Secrets of the toolbox – One Pro Cycling
Barker will continue to be involved in cycling, and is founder and CEO of the Le Col cycle clothing brand.
“It’s the right time for me to move forward, my wife and I are expecting our first child and I will be able to concentrate full time on my business, I’m sure I will be involved in cycling in one form or another I won’t be able to stay away, even if just as a fan!”
Barker is currently appearing on television as part of ITV’s Tour of Britain coverage, providing insight into the race. Barker was the highest-placed British rider in the 2005 edition of the ToB, finishing ninth.