Freeform is a radio station programming format consisting of music generally selected by a disc jockey and not confined to any particular genre. While DJs at most radio stations have little or no influence over programming structure or music selection, freeform station DJs have complete control over programming during an on-air shift and, in the U.S., are bound only by FCC regulations.

Freeform radio is largely uncommon among corporate or group-owned radio stations and is generally employed by individually-owned, non-commercial, or college radio stations. Freeform style was forged at WFMU in New Jersey, a listener sponsored station.

True freeform does, however, have recommended rules. A conscious disregard for genre-oriented playlists and programs is de rigeur for freeform, however some disc jockeys have rebelled against freeform-authority and, since they do have ultimate control over their program, focus on genre-defined playlists and stylisticly similar cuts within their sets. An alternative option is to string songs together with an abstract theme. For example, a freeform DJ might play Bob Dylan's "Subterranean Homesick Blues" followed by "Subterranean Homesick Alien" by Radiohead.

A similar concept is that of an "eclectic" station, which is likely considered to be a watered-down variation of freeform radio to some. The best-known such station is KCRW in California, which is the source of Sounds Eclectic , Morning Becomes Eclectic , and other programs distributed by Public Radio International across the United States. Other freeform/eclectic stations that have seen popularity include WXPN (Philadelphia, Pennsylvania), KCMP (Minnesota), and KEXP (Seattle, Washington). KDLD/KDLE "Indie 103.1" in California is a notable exception to the rule about corporate ownership, as it is programmed by Entravision while advertising is arranged by Clear Channel Communications. It is a highly unusual example, however, as many famous musicians host programs at the station.

The so-called "triple-A" format (adult album alternative) sometimes qualifies as freeform to a certain extent, but most triple-A stations have restrictive playlists and are largely programmed by computer.

Many freeform stations have relatively weak transmitters, especially outlets in or near large metropolitan areas where wealthier organizations tend to take over the stronger signals. Internet radio streams are commonly used to circumvent this problem. Very small stations can sometimes gain worldwide followings this way. Radio Paradise is perhaps the best-known freeform station to exclusively broadcast via the Web. At least one terrestrial station has transitioned to only broadcasting online. WOXY, based in Oxford, Ohio, had put out a small signal since the early 1980s, but shut down the transmitter in 2004 and soon began to focus on streaming.