S2 was a television station broadcast throughout the Scottish and Grampian ITV regions by SMG plc, the holder of the Scottish and Grampian region ITV franchises. S2, which aired on the Digital Terrestrial platform (branded ONdigital, at the time), was launched 30 April 1999 and closed just over two years later — as part of a deal with ITV Digital — on 27 July 2001. The channel was also broadcast on cable television services NTL and Telewest.

At launch, S2 was on air between 4pm and 2am, seven days a week, with its target audience being 16 to 34-year-olds. S2 Live, an entertainment show was S2's flagship show, and aired every night, presented by Sarah Heaney. The channel also repeated drama and documentary programmes, originally shown on Scottish/Grampian. S2 also broadcast sports coverage, including Scottish rugby.

By the end of its life, it had lost nearly all of its Scottish programmes and mainly simulcast ITV2, but covered the ITV2 graphic with an opaque S2 graphic. This caused controversy and forced the broadcaster further into removing the channel.

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: