The Quebec government is investing $246 million to build an addition to the Îlot Voyageur.
Over the summer the government sold off a major part of the abandoned Îlot Voyageur, originally meant to be a student housing complex, to be converted into condos.
Now that building is expected to get a new neighbour.
Premier Pauline Marois said the new office building will house 2,500 Revenue Québec employees, who are currently spread out across the city in several different locations.
The new 58,000 square metre building will be added to the south side of the Îlot Voyageur.
She said the project is set to be completed in 2019 and will create 200 jobs.
"This vast structural project will revitalize an area that is at the heart of the city," Marois said.
Montreal Mayor Denis Coderre welcomed the funding and the jobs it will create.
He said the project will create a "synergy" in downtown Montreal.