The former Scotland international was lately at conference side Chester.
Chester's chairman, Grenville Milington said: "Chris has had a glittering career in football for over 20 years. I'm sure that he retires with a heavy heart but I've no doubt that he will continue his relationship with professional football for many years to come, good luck Chris."
The striker played at 19 different clubs including, including a couple of clubs in Europe. Domestically, he played for sides including Colchester United, Brighton & Hove Albion, Burnley, Charlton Athletic, Stoke City and made four appearances for his country. Unfortunately for Iwelumo, his international career is remembered more for missing an open goal in a 0-0 draw with Norway at Hampden Park in 2008.
This season Iwelumo had made 10 appearances for Chester, scoring the one goal, after signing on a free transfer in the summer.