The digital television transition, also called the digital switchover (DSO), the analogue switch/sign-off (ASO), the digital migration, or the analogue shutdown, is the process in which older analogue television broadcasting technology is converted to and replaced by digital television. Conducted by individual nations on different schedules, this primarily involves the conversion of analogue terrestrial television broadcasting infrastructure to Digital terrestrial television (DTT), a major benefit being extra frequencies on the radio spectrum and lower broadcasting costs, as well as improved viewing qualities for consumers.

The transition may also involve analogue cable conversion to digital cable or Internet Protocol television, as well as analogue to digital satellite television. Transition of land based broadcasting had begun in some countries around 2000. By contrast, transition of satellite television systems was well underway or completed in many countries by this time. It is an involved process because the existing analogue television receivers owned by viewers cannot receive digital broadcasts; viewers must either purchase new digital TVs, or digital converter boxes which have a digital tuner and change the digital signal to an analogue signal or some other form of a digital signal (i.e. HDMI) which can be received on the older TV. Usually during a transition, a simulcast service is operated where a broadcast is made available to viewers in both analogue and digital at the same time. As digital becomes more popular, it is expected that the existing analogue services will be removed. In most places this has already happened, where a broadcaster has offered incentives to viewers to encourage them to switch to digital. Government intervention usually involves providing some funding for broadcasters and, in some cases, monetary relief to viewers, to enable a switchover to happen by a given deadline. In addition, governments can also have a say with the broadcasters as to what digital standard to adopt – either DVB-T, ATSC, ISDB-T, or DTMB. Governments can also require all receiving equipment sold in a country to support the necessary digital 'tuner'.

Before digital television, PAL and NTSC were used for both video processing within TV stations and for broadcasting to viewers. Because of this, the switchover process may also include the adoption of digital equipment using serial digital interface (SDI) on TV stations, replacing analogue PAL or NTSC component or composite video equipment. Digital broadcasting standards are only used to broadcast video to viewers; Digital TV stations usually use SDI irrespective of broadcast standard, although it might be possible for a station still using analogue equipment to convert its signal to digital before it is broadcast, or for a station to use digital equipment but convert the signal to analogue for broadcasting, or they may have a mix of both digital and analogue equipment. Digital TV signals require less transmission power to be broadcast and received satisfactorily.

The switchover process is being accomplished on different schedules in different countries; in some countries it is being implemented in stages as in Australia, Greece, India or Mexico, where each region has a separate date to switch off. In others, the whole country switches on one date, such as the Netherlands. On 3 August 2003, Berlin became the world's first city to switch off terrestrial analogue signals. Luxembourg was the first country to complete its terrestrial switchover, on 1 September 2006.

Different standards have been developed for the broadcast transmission of digital terrestrial television, comparable to the older analogue standards they replace: NTSC, PAL and SECAM. Broadcasters around the world choose and adopt one of these to be the format and technology behind the transmission. The standards are:

The "RRC-06" agreement in Geneva (hosted by the International Telecommunication Union (ITU)) was signed by delegates from many countries, including most of Europe, Africa and Asia. The agreement set 17 June 2015 as the date after which countries may use frequencies currently assigned for analogue television transmission for digital services (specifically DVB-T), without being required to protect the analogue services of neighbouring countries against interference. This date was generally viewed as an internationally mandated analogue switch-off date, at least along national borders—except for those operating on the VHF band which would be allowed until 17 June 2020.^{[needs update]}

These deadlines set by the agreement have been difficult to reach in certain regions, like in Africa where most countries missed the 2015 deadline, as well as South East Asia. High upgrade costs are often a reason cited for the slow transition in those regions.

The European Commission, on a different note, had recommended on 28 October 2009 that digital switchover should be completed by 1 January 2012.