A duopoly (or twinstick, referring to "stick" as jargon for a radio tower) is a situation in television and radio broadcasting in which two or more stations in the same city or community share common ownership.

United States

In the United States, the practice of duopolies has been frowned upon when using public airwaves, on the premise that it gives too much influence to one company. However, rules governing radio stations are less restrictive than those for television, allowing as many as six radio stations under common ownership in the largest U.S. media markets. Ownership of television stations with overlapping coverage areas was normally not allowed in the United States prior to 2001, even those that were not duopolies under the present legal definition, by way of being located in separate albeit adjacent markets; this required broadcasters to apply for crossownership waivers in some cases to retain full-power stations based in adjacent markets.Non-commercial educational broadcasters, mainly those that were members of the Public Broadcasting Service (PBS), were the only licensees allowed to sign-on or acquire a second television station that did not repeat the parent station's signal in the same market where they already owned a station (some of these acquired stations were originally licensed as commercial outlets).