The Night Tube will extend to the London Overground for the first time on Friday 15 December.
The 24-hour service will operate on Friday and Saturday between New Cross Gate and Dalston Junction - extending to Highbury & Islington next year.
London Overground will become the sixth line to run the late-night service.
Mayor of London Sadiq Khan said the service would "help thousands more who are working through the night or out enjoying our capital's nightlife".
About 300,000 journeys are being made every weekend on London's Night Tube service.
Due to Crossrail work taking place at Whitechapel station, London Overground night services will initially not stop at that station until works are complete.
Services are expected to call at Whitechapel from summer 2018.
This year marks the 10th anniversary of the London Overground.
The former Silverlink Metro service is run by Arriva Rail London on behalf of Transport for London (TfL).
Jonathan Fox, director of TfL's rail and sponsored services, said extending the Night Tube, would "help support thousands of people working in night-time jobs and boost the local and wider economy."