BBC One and BBC Two will be available to watch live on the internet from 27 November, at the same time as they are broadcast on terrestrial television.
Viewers will be able to view the 'simulcasts' by accessing the homepages for each channel on the BBC website.
The service will also be available on the BBC on-demand, online-TV service iPlayer, alongside BBC content broadcast over the previous seven days.
Other BBC channels, including BBC Three, BBC Four and BBC News, have been available in simulcast form for some time, along with various BBC Radio stations.
The BBC cited research by Ofcom that suggests the amount of UK consumers watching TV over the internet has doubled over the past year.