S4C (Welsh: Sianel Pedwar Cymru Welsh pronunciation: [ˈʃanɛl ˈpɛdwar ˈkəmrɨ], meaning Channel 4 Wales), currently branded as S4/C, is a Welsh television channel broadcast from the capital, Cardiff. The first television channel to be aimed specifically at a Welsh-speaking audience, it is (after BBC One, ITV, BBC Two and Sky1) the fifth oldest British television channel (Channel 4 was launched in the rest of the United Kingdom one day later).

The channel - initially broadcast on analogue television - was bilingual (Welsh and English) with most of its English-language programming being either simultaneous or deferred broadcasts of Channel 4 programmes (analogue reception of which was unavailable in most of Wales). When digital television arrived several years later, a second channel was added: a 100% Welsh-language service, branded S4C Digidol (S4C Digital). The analogue version of S4C closed on 31 March 2010, when the Wenvoe transmitter completed the digital switchover. After this, S4C Digidol became the default S4C channel available across Wales available to Welsh viewers on cable, satellite and Freeview, broadcasting only in the Welsh language.^{[citation needed]}