ITV is a British free-to-air television network with its headquarters in London. It was launched in 1955 as Independent Television, under the auspices of the Independent Television Authority (ITA) (later the Independent Broadcasting Authority, after the Sound Broadcasting Act 1972, and currently Ofcom), to provide competition to BBC Television which had been established in 1932. ITV is the oldest commercial network in the UK. Since the passing of the Broadcasting Act 1990, its legal name has been Channel 3, to distinguish it from the other analogue channels at the time, namely BBC 1, BBC 2 and Channel 4. In part, the number 3 was assigned because television sets would usually be tuned so that the regional ITV station would be on the third button, with the other stations being allocated to the number within their name.

ITV is a network of television companies that operate regional television services and also share programmes between each other to be shown on the entire network. In recent years, several of these companies have merged, so currently the fifteen regional franchises are in the hands of two companies.

The ITV network is to be distinguished from ITV plc, the company that resulted from the merger of Granada plc and Carlton Communications in 2004 and which holds the Channel 3 broadcasting licences in England, Wales, southern Scotland, the Isle of Man, the Channel Islands and Northern Ireland. With the exception of Northern Ireland, the ITV brand is the brand used by ITV plc for the Channel 3 service in these areas. In Northern Ireland, ITV plc uses the brand name UTV. STV Group plc uses the STV brand for its two franchises of central and northern Scotland.