BBC Radio is a service of the British Broadcasting Corporation which has operated in the United Kingdom under the terms of a Royal Charter since 1927. The service provides national radio stations covering the majority of musical genres, as well as local radio stations covering local news, affairs and interests. Internally, BBC Radio is now organised under the banner of BBC Audio & Music, which also oversees online audio content.

Of the national radio stations, BBC Radio 1, 2, 3, 4 and 5 Live are all available through analogue radio (5 Live on AM only) as well as on DAB Digital Radio and internet services through Real Media, WMA and BBC iPlayer. The remaining stations, BBC Radio 1Xtra, 4 Extra, 5 Live Sports Extra and 6 Music, all broadcast on digital platforms only.

All of the BBC's national radio stations, with the exception of BBC Radio 5 Live and BBC Radio 5 Live Sports Extra who broadcast from MediaCityUK in Salford, broadcast from bases in London, usually in or near to Broadcasting House. However, radio programmes are also made in the BBC's network production units located in Belfast, Birmingham, Bristol, Cardiff, Glasgow and Manchester.

The British Broadcasting Corporation (BBC) is a British public service broadcaster headquartered at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff. Its main responsibility is to provide impartial public service broadcasting in the United Kingdom, Channel Islands and Isle of Man.

The BBC is a semi-autonomous public service broadcaster that operates under a Royal Charter and a Licence and Agreement from the Home Secretary. Within the United Kingdom its work is funded principally by an annual television licence fee, which is charged to all British households, companies and organisations using any type of equipment to record and/or receive live television broadcasts; the level of the fee is set annually by the British Government and agreed by Parliament.

Outside the UK, the BBC World Service has provided services by direct broadcasting and re-transmission contracts by sound radio since the inauguration of the BBC Empire Service in December 1932, and more recently by television and online. Though sharing some of the facilities of the domestic services, particularly for news and current affairs output, the World Service has a separate Managing Director, and its operating costs have historically been funded mainly by direct grants from the British government. These grants were determined independently of the domestic licence fee and were usually awarded from the budget of the Foreign and Commonwealth Office. As such, the BBC's international content has traditionally represented – at least in part – an effective foreign policy tool of the British Government. The recent BBC World Service spending review has announced plans for the funding for the world service to be drawn from the domestic licence fee.

Radio is the transmission of signals through free space by electromagnetic waves with frequencies significantly below visible light, in the radio frequency range, from about 3 kHz to 300 GHz. These waves are called radio waves. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space.

Information, such as sound, is carried by systematically changing (modulating) some property of the radiated waves, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.

The etymology of "radio" or "radiotelegraphy" reveals that it was called "wireless telegraphy," which was shortened to "wireless" in Britain. The prefix radio- in the sense of wireless transmission, was first recorded in the word radioconductor, a description provided by the French physicist Édouard Branly in 1897. It is based on the verb to radiate (in Latin "radius" means "spoke of a wheel, beam of light, ray").