London Underground has hired cable operator Virgin to equip 120 Tube stations with WiFi networks by the end of 2012, allowing customers to access the web on smartphones, tablets and laptops.
A group of 82 stations will be first to get access to the WiFi by the end of July, including Oxford Circus, Stratford, Chancery Lane, Liverpool Street, Leicester Square and King's Cross.
The full list of stations, which will be connected in time for the London 2012 Olympics, is available here.
During an initial period the WiFi will be offered for free to all customers, but it will later be made via subscription or pre-pay models.
Virgin customers will be able to access the WiFi depending on their subscription, while everyone else will need to sign up to pay-as-you-go plans.
All customers will be able to access live Transport for London travel information for free via a new online portal.
"Our customers will soon be able to connect to the internet for live travel information while they are on the move through stations," said Gareth Powell, London Underground's director of strategy and service development,
"Bringing a next generation WiFi service to one of the world's oldest underground transport networks is progressing as planned and the forthcoming service is testing well.
"The first stations include some of our busiest and most well-known destinations and we're on-track for a successful launch this summer - all delivered at no additional cost to fare payers or tax payers."
Virgin Media and London Underground engineers have been testing the WiFi service.
This includes capacity testing at the Chancery Lane station, involving hundreds of devices being connected to the network at the same time, simulating the load of a platform full of customers all accessing WiFi.
Jon James, Virgin Media executive director of broadband, said: "In partnership with TfL, we've been working around-the-clock to install and test WiFi on London Underground and are about to connect some iconic and world famous Tube stations with a WiFi service London will be proud of."
Millions of London Overground passengers will also be able to access free WiFi at every station on the network from this summer after a deal was signed with the Sky-owned WiFi provider The Cloud.