The Joint Committee on Administrative Rules is a bipartisan legislative oversight committee created by the General Assembly in 1977. Pursuant to the Illinois Administrative Procedure Act, the committee is authorized to conduct systematic reviews of administrative rules promulgated by State agencies.

JCAR is composed of 12 legislators who are appointed by the legislative leadership, with the membership apportioned equally between the two houses and the two political parties. It is co-chaired by 2 members representing each party and each legislative house. Support services for the committee are provided by the JCAR staff.

Two purposes of JCAR are to ensure that the General Assembly is adequately informed of how laws are implemented through agency rulemaking and to facilitate public understanding of rules and regulations. JCAR also publishes a weekly newsletter called The Flinn Report and maintains the State's database for the Illinois Administrative Code and Illinois Register.