The landmark building on Lichfield Street, which was built in 1906, will shut on December 23, with work starting on January 5.
A temporary seven-days-a-week service will open at the former Town Hall restaurant once the renovation gets under way.
The revamp comes after Walsall Council shut nine other libraries across the borough in June, leaving just seven open.
The work will see Central Library redesigned as a ‘hub’, incorporating the local history centre and archive, a cafe, and computer lounge.
Councillor Ian Shires, portfolio holder for community and leisure, said: “I am pleased to see that the landmark Central Library is staying in its original location but with the benefit of major enhancements and relocated archives.
“It is a fairly big project, but importantly a temporary town library service will also be in operation while work is under way.
This will also be a modern library service that reflects training, education needs and aspirations in the borough.”
Beechdale, Blakenall, New Invention, Pelsall, Pleck, Pheasey, Rushall, South Walsall and Walsall Wood libraries all closed as the authority looked to save £86m by 2020.
Mayor of Walsall and library campaigner, Councillor Marco Longhi, welcomed the revamp – but said the closure of his local site was still ‘the wrong decision’.
He said: “I think that any improvements to libraries is something that should be welcomed and I am sure that the work will massively benefit Central Library.
“But it still confuses me how libraries across the borough were closed when there was such support for them to remain open, particularly in Pelsall where our library was built only four years ago, opened by a member of the Royal family and hailed as an excellent facility from outside bodies.
“We had great footfall, we ran the library in a cost-effective way and I still maintain it was the wrong decision.”