A £145 million contract has been awarded to build more than 100 rail carriages for the Gatwick Express line.
The 27 new four-carriage trains to be built by Bombardier will replace 1980s-built rolling stock that has been operating on the line since 2008.
The Electrostar trains will have “easier access for passengers with luggage, improved storage space, two by two seating and Wi-Fi,” a Govia Thameslink Railway (GTR) spokesman said.
New trains will also be added to Thameslink routes and are due to enter service in 2016.
Rail minister Claire Perry said the trains would be a boost for both passengers and the economy.
“They will transform journeys on the Gatwick Express and Thameslink routes and safeguard jobs at Bombardier’s Derby factory,” she said.
Charles Horton, chief executive of GTR and managing director of Southern, said: “This is great news for our Gatwick passengers, but also for those travelling from Brighton, as in the off-peak some of these trains will be extended to there, while still maintaining the fast connection between Victoria and Gatwick.
“We took over the operation of the Thameslink route in September and already we are introducing new trains which will transform our passengers’ journeys on services between Bedford and Brighton.”