Trains will run through the night on Fridays and Saturdays, joining the Central and Victoria lines which resumed night services in November.
The Northern and Piccadilly line night services will return in the summer, TfL says.
The National Union of Rail, Maritime and Transport Workers (RMT) has not ruled out strike action.
The Night Tube was suspended in March 2020 due to the coronavirus pandemic.
The return of the Night Tube has also been unpopular with the union.
Strike action by the RMT has severely hampered the service since its resumption in November.
In January, the union said its drivers would be striking every Friday and Saturday night for six months, following on from strikes in December.
TfL says that despite the action, both the Victoria and Central lines are running on weekends.