Digital switchover for London from 4 April 2012
The London TV region's analogue signal will be switched off from 4 April 2012, Digital UK has said.
A third of UK homes have already switched to digital, but the London region is set to be the biggest.
Some 12 million viewers will be affected in the London area and Digital UK estimates that four million analogue sets need to be converted.
The Central, Yorkshire and Anglia regions are switching in the next few months.
Analogue BBC Two will disappear in London and neighbouring parts of Berkshire, Essex, Hertfordshire, Kent, Middlesex and Surrey on 4 April 2012.
The remaining analogue channels - BBC One, ITV1, Channel Four and Channel Five - will then be turned off on 18 April 2012.
BBC media correspondent Torin Douglas said: "TV's digital switchover has gone pretty smoothly so far.
"Nine out of 10 homes have at least one digital set and eight-and-half million homes have had their analogue signal switched off."
Stressing the importance of a smooth switchover in London, our correspondent added: "With the London Olympics and the Queen's Diamond Jubilee next year, the timing will be crucial if viewing is not to be disrupted."
Digital UK said the move, three months before the Olympics, "will give local viewers a choice of ways to enjoy widescreen, interactive digital coverage of the Games".
The switchover announcement comes 75 years after the first regular TV service began in London.