Woodside Library shut in June to allow £40,000 of repair work to be carried out.
Glasgow Life, which runs the city's libraries, said there had been a long-term problem with the domed roof which was leaking.
It was decided to redecorate parts of the building while work was going on.
During the closure, library users were urged to visit the nearest alternatives which were Hillhead on Byres Road, the Mitchell on North Street and Maryhill Library on Maryhill Road.
A Glasgow Life spokesman said: "Woodside Library is one of the best known landmarks in the West End providing vital services to the local community."
Woodside will reopen tomorrow with an open day.
Planned activities include book promotions and face-painting.
A Glasgow Life spokesman said: "There will also be a particular emphasis on the Chinese book collection, as there is a large Chinese community in the Woodside area."