Cash machines which dispense euros as well as pounds have been installed at Elephant & Castle, London Bridge and Waterloo Underground stations.
The three SE1 tube stations are among 70 across the capital where new Raphaels Bank dual-currency ATMs have been installed.
Euro withdrawals are commission free, with rates intended to be more favourable than the largest currency exchange providers.
"As part of our ongoing plans to improve the services on offer for our customers, we have worked with Raphaels Bank to install these cash points at stations across our network," said Graeme Craig, director of commercial development at Transport for London.
"Millions of people use our network each year, including going to or from an airport, Eurostar and coach stations, and these machines have been installed to make it easier for people to access the currency they need.”
Transport for London commissioner Sir Peter Hendy recently revealed that since the first euro ATMs were installed at tube stations in November, €2.5 million has been dispensed across the network.