Pacifica Foundation is an American nonprofit organization that owns five independently operated, non-commercial, listener-supported radio stations known for their progressive/liberal political orientation. Its national headquarters adjoins station KPFK in North Hollywood, California.

Pacifica Foundation also operates the Pacifica Network, a program service supplying over 200 affiliated stations with various programs, primarily news and public affairs. It was the first public radio network in the United States and is one of the world's oldest listener-funded radio networks. Programs such as Democracy Now! and Free Speech Radio News have been some of its most popular productions.

Pacifica was founded in 1946 by pacifists E. John Lewis and Lewis Hill. During World War II, both of them had filed for conscientious objector status. After the war, Lewis, Hill and a small group of former conscientious objectors created the Pacifica Foundation in the town of Pacifica, California, in the San Francisco Bay Area. Their first station, KPFA in Berkeley, commenced broadcasting in 1949. By 1977, the network had added WBAI in New York City, KPFK in Los Angeles, WPFW in Washington, DC, and KPFT in Houston.

In 1973, one of Pacifica's stations, WBAI, broadcast comedian George Carlin's Filthy Words routine uncensored. Following a listener complaint, Pacifica received a letter of reprimand from the FCC, censuring them for allegedly violating broadcast regulations which prohibited airing indecent material. The foundation took the matter to the U.S. Supreme Court in FCC v. Pacifica Foundation and lost in a 5–4 decision. This became a landmark moment in the history of free speech, and the case continues to define the power of the government over broadcast material it calls indecent.

In two years during a three-year cycle, subscribers and station staff at each station vote to elect the Local Station Board, as required by the Pacifica Foundation bylaws. The local station boards have support and advisory duties for their station. They also elect members from their body to serve on the Pacifica Foundation's national board of directors. The full local station board meets monthly, and committees of the local station board meet on both regular and ad hoc bases.

For most of its history, Pacifica gave each of its stations independent control of programming. During the 1990s, a major controversy arose over rumors that the Pacifica National Board and national staff were attempting to centralize control of content, to increase audience. The rumors included accusations that the board proposed changing the network's funding model away from a reliance exclusively on listener donations and toward a mix of listener donations and corporate foundation funding similar to that of NPR. There were also accusations that the Board was considering selling both KPFA and WBAI in New York City, which operate on commercial-band FM frequencies (94.1 and 99.5, respectively) worth hundreds of millions of dollars.

This led to years of conflict, including court cases, public demonstrations, firings and strikes of station staff, whose common plight inspired creation of Radio4all.net to preserve what they saw as the original spirit of Pacifica. Many listeners of the individual stations, especially KPFA and WBAI, objected to what they saw as an attempt to tone down the overtly left-leaning political content on Pacifica stations. The controversy included highly publicized ideologically charged disputes between grassroots listener organizations and Mary Frances Berry, a former chairperson of the U.S. Commission on Civil Rights, who chaired Pacifica's national board at the time.

The board eventually was embroiled in counter-lawsuits by board members and listener-sponsors and, after global settlement of the lawsuits in November 2001, an interim board was formed to craft new bylaws, which it did in two tumultuous years of national debates among thousands of listener-sponsors and activists, finally giving listener-sponsors the right and responsibility to elect new Local Station Boards at each of the five Pacifica stations. These local boards in turn elect the national board of directors. Aside from some minor changes, the same 2003 bylaws remain in effect today.^{[citation needed]}