Public Wi-Fi is available within London Underground and Elizabeth line stations. This service works very well with millions of connections every day. Free on-train Wi-Fi is also available on the above ground sections of the Elizabeth line in the newer Class 710 London Overground trains.

By early 2026, the London Underground has transitioned from traditional Wi-Fi hotspots to a comprehensive 4G and 5G mobile network across almost all lines. As of March 2026, the Elizabeth Line is fully connected with high-speed data in all tunnels and stations. Significant portions of the Northern Line (from Archway to Euston and through the Battersea extension), the Jubilee Line (east of Westminster), and the Central Line (between Holland Park and Queensway) also feature full tunnel connectivity. The project, managed by Boldyn Networks and TfL, aims to have the entire network—including deep-level tunnels on the Piccadilly and Bakerloo lines—connected by the end of 2026. While traditional "station Wi-Fi" (provided by Virgin Media) is still available at over 260 platforms, the focus in 2026 is on seamless mobile data, allowing commuters to stream video and make calls without interruption while traveling underground. This massive infrastructure overhaul has turned one of the world's oldest subway systems into one of the most digitally connected.