Minimum age 18 with parents consent, with no consent the minimum age is 21.
FOID Card - The New and Updated Guide for 2018.
The actual statutes do not say that:
§ Sec. 430 ILCS 65/4 Application for Firearm Owner's Identification Card
(a) Each applicant for a Firearm Owner's Identification Card must:
(1) Make application on blank forms prepared and furnished at convenient locations throughout the State by the
Department of State Police, or by electronic means, if and when made available by the Department of State Police;
and
(2) Submit evidence to the Department of State Police that:
(i) He or she is 21 years of age or over, or if he or she is under 21 years of age that he or she has the written
consent of his or her parent or legal guardian to possess and acquire firearms and firearm ammunition and that
he or she has never been convicted of a misdemeanor other than a traffic offense or adjudged delinquent,
provided, however, that such parent or legal guardian is not an individual prohibited from having a Firearm
Owner's Identification Card and files an affidavit with the Department as prescribed by the Department stating that
he or she is not an individual prohibited from having a Card;
And what contexts are those?
At the very least, a minor of his age can legally carry and transport a firearm to use for hunting, at a gun range, hunter safety course, etc. There are no exceptions listed in the statutes, but there's always the possibility that case law has made a "in the spirit of the law" restriction.
