The ex-Republic of Ireland international enjoyed a 16-year playing career, taking in spells with clubs in Ireland, England and the United States.
Doyle, who most recently represented Colorado Rapids in Major League Soccer, has cited concerns about the risks associated with repeatedly heading a football as the reason behind his early retirement from the sport.
"Today I'm sad to announce that after listening to medical advice I will no further part in this season and will be retiring," he said in a statement. "This year it has been clear to me that heading the ball was becoming problematic, and causing me to have repeated headaches.
"Two concussions this season and numerous others over the years have made this more concerning. After consulting with experts in the field it has been decided that to avoid the possibility of these symptoms become more serious and permanent, I will be hanging up my boots for good.
"I've really enjoyed my time with the Colorado Rapids and playing in MLS has been a fantastic experience. I would have loved to have taken the opportunity offered to stay for another year. The staff, players and fans here have made me, and more importantly, my family feel at home in Denver and we will miss it."
Doyle started his senior playing career at St Patrick's Athletic in 2002, before later moving on to Cork City, Reading and Wolves, while also spending time on loan at Queens Park Rangers and Crystal Palace.