It was closed to customers in the autumn after a small section of the ceiling of the Grade II*-listed building came loose, causing a piece of the glass panelled roof to fall to the ground.
Councillor Elias Mattu, Wolverhampton City Council's Cabinet Member for Leisure and Communities, said: "I'd like to thank customers for bearing with us while this important remedial work was carried out.
"Because the building is Grade II*-listed we had to get special permission from English Heritage to carry out the work, and specialist contractors were required to conduct the repairs.
"The work has now been complete and the library is fully open once more."
While the first floor area was closed, many items were relocated to the adult lending library on the ground floor, while other items were made available to customers on request.
- released: Wednesday 7 January, 2015