Digital terrestrial television in the United Kingdom encompasses over 100 television, radio and interactive services broadcast via the UK's terrestrial television network and receivable with a standard television aerial. The majority of services, including those from the existing five analogue broadcasters, are broadcast free-to-air, and a further selection of encrypted Pay-TV services (such as ESPN) are also available.

Three companies provide DTT services in the UK: Freeview, Top Up TV, and (some) BT Vision. Freeview channels account for most, although not all, of the total available channels broadcast on digital terrestrial television, available at no extra cost and requiring no subscription other than payment of the annual TV licence fee. Top Up TV is a subscription service offering channels such as Sky Sports and ESPN, as well as on-demand content. BT Vision offers only Sky Sports and ESPN on DTT - their other services are carried via IPTV signals.

The digital broadcasting technology adopted in the UK is the DVB-T system (Digital Video Broadcasting – Terrestrial) carrying compressed digital audio, video and other data in a combined transport stream, using COFDM modulation. A total of six 'multiplexes' are broadcast in the UK, guaranteed to reach over 90% of the country when analogue signals are fully switched off. Three of the six multiplexes, carrying the free public service channels operated by the BBC, ITV, Channel 4, S4C and Channel 5, are guaranteed wider coverage still, reaching 98.5% of the country including areas dependent on low-power local relays.

Public television broadcasting started in the United Kingdom in 1936, and now has a collection of free and subscription services over a variety of distribution media, through which there are over 480 channels for consumers as well as on-demand content. There are six main channel owners who are responsible for most viewing. There are 27,000 hours of domestic content produced a year at a cost of £2.6 billion. Analogue terrestrial transmissions are currently being switched off and this is due to be completed in 2012.

Free and subscription providers are available, with differences in the number of channels, capabilities such as the programme guide (EPG), video on demand (VOD), high-definition (HD), interactive television via the red button, and coverage across the UK. Set-top boxes are generally used to receive these services; however Integrated Digital Televisions (IDTVs) can also be used to receive Freeview or Freesat. Top Up TV and BT Vision utilise hybrid boxes which receive Freeview as well as additional subscription services. Households viewing TV from the internet (YouTube, Joost, downloads etc.) are not tracked by Ofcom. The UK's five most watched channels, BBC One, BBC Two, ITV, Channel 4 and Channel 5, are available from all providers.

The United Kingdom of Great Britain and Northern Ireland (commonly known as the United Kingdom, the UK, or Britain) is a sovereign state located off the north-western coast of continental Europe. The country includes the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands. Northern Ireland is the only part of the UK that shares a land border with another sovereign state—the Republic of Ireland. Apart from this land border the UK is surrounded by the Atlantic Ocean, the North Sea, the English Channel and the Irish Sea.

The United Kingdom is a unitary state governed under a constitutional monarchy and a parliamentary system, with its seat of government in the capital city of London. It is a country in its own right and consists of four countries: England, Northern Ireland, Scotland and Wales. There are three devolved administrations, each with varying powers, based in Belfast, Edinburgh and Cardiff, the capitals of Northern Ireland, Scotland, and Wales. Associated with the UK, but not constitutionally part of it, are three Crown Dependencies. The United Kingdom has fourteen overseas territories. These are remnants of the British Empire which, at its height in 1922, encompassed almost a quarter of the world's land surface and was the largest empire in history. British influence can still be observed in the language, culture and legal systems of many of its former territories.

Digital terrestrial television (DTTV or DTT) is the technological evolution of broadcast television and an advancement of analog television. DTTV broadcasts land-based (terrestrial) signals. The purposes of digital terrestrial television, similar to digital versus analog in other platforms such as cable, satellite, and telecommunications, are to reduced use of spectrum and to provide more capacity than analog, provide better-quality picture, and to lower operating costs for broadcast and transmission after the initial upgrade costs. A terrestrial implementation of digital television (DTV) technology uses aerial broadcasts to a conventional television antenna (or aerial) instead of a satellite dish or cable television connections.

Competing variants of broadcast television systems are being used around the world. Advanced Television Standards Committee created the ATSC standards that use an ATSC tuner in North America and South Korea—an evolution from the analog National Television Standards Committee (NTSC) standard. Integrated Services Digital Broadcasting (ISDB-T) is used in Japan, with a variation of it being used in most of South America. DVB-T is the most prevalent, covering Europe, Australia, New Zealand, Colombia and some countries of Africa. DMB-T/H is China's own standard (including Hong Kong, though Hong Kong's cable operators use DVB); the rest of the world remains mostly undecided, many evaluating multiple standards. ISDB-T is very similar to DVB-T and can share front-end receiver and demodulator components. Several European countries have switched from analog to digital terrestrial television, with the rest hoping to have completed the switchover mostly by 2012.