R25 was a proposed railway orbital around the Zone 3 area of London, England. First proposed in the Mayor of London's £1.3 trillion London Infrastructure 2050 plan, the line would have used some existing Network Rail and London Overground lines, linked by stretches of new railway.
There have also been calls to extend the line further south across the river to Thamesmead and Abbey Wood.[2][3] In August 2017, the Government granted permission for the extension of the Gospel Oak to Barking line and a provision for a stop at Renwick Road (if needed) and states that a further extension across the Thames should be provisioned.[4][5] The new station at Barking Riverside opened on 18 July 2022,[6] but any further extension across the river was dropped in favour of extending the Docklands Light Railway from Gallions Reach.
City Metric have produced a map of what the R25 might look like in detail.[7]