The 9-0-4 Amateur Radio Club is an Illinois not-for-profit corporation, which exists for the purpose of furthering amateur radio interests in its service area.

Membership is open to any licensed amateur radio operator, and associate membership is open to anyone interested in amateur radio.

The club's service area is Southern Illinois, Southeast Missouri, and Western Kentucky. The United States is divided into ten call sign areas. Illinois is located in Area 9, Missouri is in Area 0 and Kentucky is in Area 4. For this reason the numbers 9, 0, and 4 appear in the club name.

The club's call sign is K9IM. Although in the standard phonetic alphabet this would be "Kilo Nine India Mike," the informal phonetics of "Kentucky Nine Illinois Missouri" are quite descriptive.

The club is active in emergency preparedness and public service activities. It maintains a repeater, situated at the confluence of the Ohio and Mississippi Rivers in historic Cairo, Illinois.

The 9-0-4 ARC is affiliated with the American Radio Relay League (ARRL) which is the pre-eminent national organization of radio amateurs in the United States.