BBC One and BBC Two will be available to watch live online from 27 November, Jana Bennett, Director of BBC Vision, announced today.
The channels join BBC Three, BBC Four, CBBC, CBeebies and BBC News which are already simulcast.
They can all be watched online via their channel sites on bbc.co.uk through a wide range of internet enabled devices. They can also be watched through BBC iPlayer.
Jana Bennett said: "The launch of BBC One and BBC Two online completes our commitment to make our portfolio of channels available to watch on the internet.
"From 27 November licence fee payers will be able to watch BBC programmes, live, wherever they are in the UK on their computers, mobile phones and other portable devices.
"Through iPlayer and series stacking, they'll have the option to catch up with them later."
Research by Ofcom reveals that UK consumers watching TV online has doubled in the last 12 months.
In the United States, reports show around nearly 20% of households with internet access use it to watch television broadcasts either via channel sites or YouTube, double the number two years ago [see Notes to Editors 2].
Simon Nelson, Controller of BBC Vision Multiplatform and Portfolio, said: "Simulcasting BBC One and BBC Two is a huge advance in making our portfolio of multiplatform channels available to our audiences, and giving them the opportunity to discover the wealth of associated content the BBC is able to offer through our channel and programme sites."