Cuatro (stylized as cuatro^o, "Four") is a Spanish commercial television channel, on air since November 2005. Owned by Mediaset España Comunicación, it is broadcast on the TV frequencies licensed to the previous owner Sogecable in 1990 and previously used by them for the analogue transmission of its pay-per-view channel Canal+.

In 2006, Cuatro scored a massive coup by striking a deal with the Royal Spanish Football Federation and Spain's national football team allowing it to show all of the team's matches, and it also concluded an agreement with rival channel La Sexta to share the rights to broadcast the games of general interest in the 2006 FIFA World Cup. It snatched this licence from TVE, who had held the rights to the national team's matches for years. In 2008, together with satellite platform Digital+, owned by the same company, Cuatro secured the rights to broadcast the UEFA Euro 2008 championship, scoring the highest ratings in the history of Spanish television (since 1992). The two broadcasters also achieved rights for 2010 FIFA World Cup.

Cuatro is Spanish (and other Romance languages) for the number four. It may also refer to:

A television channel is a physical or virtual channel over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the broadcast or cable band of 54 to 60 MHz, with carrier frequencies of 55.25 MHz for NTSC analog video (VSB) and 59.75 MHz for analog audio (FM), or 55.31 MHz for digital ATSC (8VSB). Channels may be shared by many different television stations or cable-distributed channels depending on the location and service provider.

Depending on the multinational bandplan for a given region, analog television channels are typically 6, 7, or 8 MHz in bandwidth, and therefore television channel frequencies vary as well. Channel numbering is also different. Digital television channels are the same for legacy reasons, however through multiplexing, each physical radio frequency (RF) channel can carry several digital subchannels. On satellites, each transponder normally carries one channel, however small, independent channels can be used on each transponder, with some loss of bandwidth due to the need for guard bands between unrelated transmissions. ISDB, used in Japan and Brazil, has a similar segmented mode.

Channel, Channels, and similar terms may refer to: