This will see the long-awaited new bus station built, alongside 318 private rental flats and 100,000 sq ft of offices.
Contractor ISG is understood to be in the frame to deliver the delayed £100m project. The entire scheme is expected to take between two years to 30 months to complete.
The project includes a bus station with 14 stands, seven ground floor shops, and flats in a 22-storey tower facing Wood Street and a nine-storey block facing Marland Street.
The bus station project was originally due to open last year but due to changes in the wider plans the project will now be completed in 2021.
Huw Thomas, Leader of Cardiff Council, said: “The building of a new bus interchange has been a number one priority for the council since day one of this administration, reflecting our commitment to delivering more and better jobs for the people of Cardiff and beyond.
“This will be the final stage of the completion of Central Square, which is the biggest regeneration project in Wales.”
Cardiff-based developer Rightacres is behind the wider Central Square project in front of Cardiff Central Railway Station.