It is estimated that about 100,000 people moved out of Belfast in the 1970s and 1980s.
Now the council is trying to encourage people to come back and hopes 66,000 more people will move into the city.
Council leaders believe that a bigger, better Belfast will be good for Northern Ireland.
The council have launched an ambitious long-term plan, the Local Development Plan (LDP), on how the development of the city will be planned to 2035.
During the Troubles, the population of the city dropped dramatically and economic development was hit hard.
The current population of Belfast is about 340,000 and the aim is to increase the total to above 400,000.
Councillor Peter Johnston, chair of Belfast City Council's planning committee, said: "It's absolutely critical that we plan for and stimulate Belfast's growth.
"Our Local Development Plan will have an impact on everyone who lives in, works in and visits Belfast, because it will shape how Northern Ireland's capital city grows and becomes more competitive in the future."
No firm details have been announced about how exactly the council plans to do it.
A public consultation will take place before concrete plans are announced.
The council is holding a number of information sessions to allow people to give their views.
A plan to bring the population of Belfast up to pre-Trouble levels has been launched by Belfast City Council.