The first ever Night Tube services will launch on the Central and Victoria lines on Friday, offering a 24-hour service on Fridays and Saturdays.
Expansion to the Jubilee, Northern and Piccadilly lines will follow in autumn.
More than 100 police officers will be deployed to patrol the 144 stations that will now stay open throughout Friday and Saturday night.
Fears have been raised about the safety of the service, but Mayor Sadiq Khan has provided £3.4 million to cover the cost of the extra shifts.
Khan said: “The opening of the Night Tube marks the start of an exciting new chapter in London’s life.
“It will unlock the full potential of London’s night time economy and support the thousands of Londoners who travel to or from work at night.”
The long-awaited extension of the service comes after night bus usage has increased by 173% since 2000.
Transport for London also claim that by supporting the night-time economy, the 24-hour service will help boost the economy by £360 million.
Trains on the Jubilee and Victoria will run on average every 10 minutes, with standard off-peak charges applying.