In the broadcasting industry (especially in North America), a network affiliate (or affiliated station) is a local broadcaster which carries some or all of the programme line-up of a television or radio network, but is owned by a company other than the owner of the network. This distinguishes such a station from an owned-and-operated station (O&O), which is owned by its parent network.

In the United States, Federal Communications Commission (FCC) regulations limit the number of network-owned stations as a percentage of total market size. As such, networks tend to have O&Os only in the largest media markets (eg. New York City and Los Angeles), and rely on affiliates to carry their programming in other markets. However, even the largest markets may have network affiliates in lieu of O&Os. For instance, Tribune Broadcasting's WPIX serves as the New York City affiliate for the CW Television Network, which does not have an O&O in that market. On the other hand, several other TV stations in the same market — WABC (ABC), WCBS (CBS), WNBC (NBC), WNYW (Fox) and WWOR (MyNetworkTV) — are O&Os.

In Canada, the Canadian Radio-Television and Telecommunications Commission (CRTC) has significantly more lenient rules regarding media ownership. As such, most television stations, regardless of market size, are now O&Os of their respective networks, with only a few true affiliates remaining. The Canadian Broadcasting Corporation originally relied on a large number of privately-owned affiliates to disseminate its radio and television programming. However, since the 1960s, most of the CBC Television affiliates have been replaced by network owned and operated stations or retransmitters. CBC Radio stations are now entirely O&O.

While network-owned stations will normally carry the full programming schedule of the originating network, an affiliate is independently-owned and typically under no obligation to do so. Affiliated stations often buy supplementary programming from another source, such as a syndicator or another television network which does not have coverage in the station's broadcast area, in addition to the programming they carry from their primary network affiliation.

Dual affiliations

In some smaller markets in the United States, a station may even be simultaneously listed as an affiliate of two networks. A station which has a dual affiliation is typically expected to air all or most of both networks' core prime time schedules — although programming from a station's secondary affiliation normally airs outside of its usual network time slot, and some less popular programs may simply be left off a station's schedule. Dual affiliations are most commonly associated with the smaller American television networks, such as MyNetworkTV and The CW, which air fewer hours of prime time programming than the "Big Four" networks and can thus be more easily combined into a single schedule, although historically the "Big Four" have had some dual-affilate stations in small markets as well.