Keepmoat Homes was selected following a structured procurement process that saw 17 developers invited to bid to carry out the regeneration work.
Plans include 134 homes, shops, building a hotel and a 200-space multi-storey car park.
Building work on the project could begin at the end of November, the council said.
The development is also expected to mark the start of further improvements in the town centre, including the area around Market Square and the potential development of the Tresham College site.
Councillor Graham Lawman, Chairman of Wellingborough Council’s Development Committee, said: “This is a really exciting time for Wellingborough. We are talking about tens of millions of pounds being invested into our town centre, and the beginning of a major improvement project which will extend further than just this one site.”
The council has spent £3.5m buying land to start the project.