London's Westminster, Kensington and Chelsea districts will be delivered the largest free wireless zone in Europe.
The deal between British carrier O2 and two councils will apparently come at no cost to taxpayers, however terms of the deal were not disclosed.
O2 announced its plans in January 2011 to offer free wi-fi across Britain that would be funded by advertising.
The plan is to provide the service in time for Queen Elizabeth's Diamond Jubilee and the 2012 London Olympics, which start in late July, to allow visitors and residents to get more out of their stay.
O2 says the free network will be available "throughout" the named locations, but it will commence with a limited number of areas in January and has not said when the network will be complete.
According to O2, the network will be the largest free wi-fi hub in Europe.
In Westminster alone, it could be providing internet access to half a million tourists each day, 250,000 residents and 500,000 workers.
"Next summer’s Olympic Games mean that London will be putting on the biggest show on earth and as Westminster has a starring role, visitors to London will easily be able to share their pictures and updates of the Olympic events across social networking sites,” said Councillor Philippa Roe, Cabinet Member for Strategic Finance at Westminster City Council.