Renovations on the clock tower of the Gallery of Modern Art in Royal Exchange Square began in May last year.
The Â£400,000 project saw the tower and weather vane, which date back to 1827, cleaned, restored, and reinstated.
More extensive repairs were needed when some masonry, dating back almost 200 years, was found to be wrongly bedded.
The Gallery of Modern Art, is run by Glasgow Life, Glasgow City Council's arms-length body which overseas culture, arts and sports venues.
Depute council leader and chair of Glasgow Life, Councillor Archie Graham, said the work would ensure "generations to come have the opportunity to enjoy this beautiful building".
"The Gallery of Modern Art is a building firmly tied to the history of Glasgow itself," he said.
"We are delighted to reveal the restored clock tower and weather vane, in complete working order just in time for its 200th anniversary.
The building was originally constructed in 1778 as the townhouse of William Cunninghame of Lainshaw, one of Glasgow's wealthy tobacco lords.
It later became a bank in 1817 when it was enlarged to create the Royal Exchange.
It was this work which added the Corinthian pillars of the temple frontage to Queen Street and the Cupola and clock tower design.
The Royal Exchange was later purchased by Glasgow Corporation in November 1949 for Â£105,000.
David Millar, head of conservation at Austin-Smith:Lord architects, which led the project, said the restoration had been "a very interesting and challenging" experience.
"There is always a level of risk associated with removing paint from sandstone but it's an exciting activity as you don't know what you might find," he said.
"We discovered masonry wrongly bedded and sandstone heavily carbonated and although some individuals might like to see these dark deposits removed it's not good practice as you are potentially removing too much original historic and listed fabric.
"We have steam cleaned and removed loose material and carried out indent repairs and what we have represented follows good conservation practice. We think the final result is both beautiful and able to stand the test of time."
The restoration work was undertaken by City Building Group and CBC Stone, with financial support from Historic Environment Scotland.
Restoration work has been completed on one of Glasgow's most famous buildings - during which serious errors in the original construction were repaired.