The 2004 blaze destroyed 37 paintings and 50,000 books, all of them hundreds of years old. It also revived Germany's trauma over the loss of irreplaceable archives and libraries to bombs during World War II.
The fire was caused by an electrical malfunction.
When the library reopens Wednesday, it will have 60,000 of its original volumes, said director Michael Knoche. Thousands more are still being repaired. Restoration work is expected to continue until 2015.
Goethe's literary treasures
The restoration has cost 12.8 million euros ($18.2 million) as workers have painstakingly restored not only the books, but the building itself, including the library's famous Rococo room. The reading room is a lofty gilded gallery with busts of poets, paintings and bookcases set against white walls.
"It has always been more than just a library," said Hellmut Seemann, head of the foundation managing the library, saying visitors regarded it as a shrine to German classicism.
Built in 1691, the library specializes in German literature between 1750 and 1850 and houses some one million books, including many rare first-editions and the largest collection of Faust by Johann Wolfgang Goethe. Goethe, one of Germany's best-known authors, worked as a librarian at the Anna Amalia.
Weimar, a city about 250 kilometers (150 miles) southwest of Berlin in the eastern German state of Thuringia, is the region's cultural center. It also served as the backdrop for the German republic, which was declared there in 1919.
On the day of the fire, as flames licked at the library's roof, people formed a human chain to save as many books as possible. They salvaged some 6,000 historical works, including a 1543 Martin Luther.
Since then, some 22,000 German firms and people donated funds to repair the Anna Amalia, or to pay to repair books or buy replacements. Library staff estimates that two of every three of the lost books can be bought from other collections or in auctions.
"It was the worst library fire in Germany since the War," said Jens Goebel, culture minister of Thuringia, at the start of a week of celebrations to mark the opening.
The official reopening will be presided over by German President Horst Köhler.