Community radio is a radio service offering a third model of radio broadcasting in addition to commercial and public broadcasting. Community stations serve geographic communities and communities of interest. They broadcast content that is popular and relevant to a local, specific audience but is often overlooked by commercial or mass-media broadcasters. Community radio stations are operated, owned, and influenced by the communities they serve. They are generally nonprofit and provide a mechanism for enabling individuals, groups, and communities to tell their own stories, to share experiences and, in a media-rich world, to become creators and contributors of media.

In many parts of the world, community radio acts as a vehicle for the community and voluntary sector, civil society, agencies, NGOs and citizens to work in partnership to further community development aims, in addition to broadcasting. There is legally defined community radio (as a distinct broadcasting sector) in many countries, such as France, Argentina, South Africa, Australia and Ireland. Much of the legislation has included phrases such as "social benefit", "social objectives" and "social gain" as part of the definition. Community radio has developed differently in different countries, and the term has somewhat different meanings in the United Kingdom, Ireland, the United States, Canada, and Australia.

U.S. community radio stations are usually staffed by volunteers and air a wide variety of programming. They generally have smaller budgets than National Public Radio (NPR) network outlets, due to the small audience of potential contributors and business donors, and may use web-based software such as Spinitron to track their playlists. Community radio stations are distinct from NPR stations; most community-radio programming is locally produced by non-professional disc jockeys and producers (although a few have honed their skills well enough to launch professional radio careers), whereas NPR relies more on syndicated programming (from its own sources and other outlets such as PRI). NPR stations almost always have paid staffs to handle most duties. Community stations often try, as a matter of principle, to reduce their dependence on financial contributions from corporations (and governments, in comparison with other public broadcasters).
Parade at the launch of WXOJ-LP, Valley Free Radio, in Northampton, Massachusetts in August 2005

Many community stations are licensed as full-power FM stations, while others (especially newer community stations founded after 2005) are licensed under low-power broadcasting rules. Many of the former were founded in the 1960s and 1970s when cultural experimentation (such as the New Left) in the U.S. had a significant following, particularly among the young. Some of the largest and best-known community radio stations are those owned by the non-profit Pacifica Foundation, including WBAI in New York; WPFW in Washington, D.C.; KPFA in Berkeley, California (which covers the San Francisco area) KPFK in Los Angeles and KPFT in Houston, TX (which also covers Huntsville, Goodrich, Livingston, and Galveston). Many community radio stations are affiliates of the Pacifica Radio Network, like WXOJ-LP in Northampton, Massachusetts.

The National Federation of Community Broadcasters was formed in 1975 as an umbrella organization for community-oriented, noncommercial radio stations. The NFCB publishes handbooks for stations and lobbies on behalf of community radio at the federal level. It has been criticized for encouraging the homogenization of community stations through its Healthy Station Project. The project encouraged stations to scale back volunteers' power over management and the content of their programs, as well as embrace more-predictable "strip" programming.[29] The Grassroots Radio Coalition is a loose coalition of stations which formed as a reaction against increasing commercialization of public radio and lack of support for volunteer-based stations (including those belonging to the NFCB). Some stations are members of both groups.

In the U.S., community radio stations are non-profit, community-based operations licensed by the Federal Communications Commission for broadcasting in the non-commercial public portion of the FM band. These stations differ from other public radio outlets in the U.S. by allowing community volunteers to actively participate as broadcasters