Fiolstræde is a pedestrianised shopping street in central Copenhagen, Denmark. It passes the square Frue Plads on its way from Nørreport station in the north to Skindergade in the south where Jorcks Passage connects it to the shopping street Strøget. Copenhagen Cathedral is located in the street which also passes the rear side of Copenhagen University Library.
The area along the street was until the 17th century dominated by green areas and the more likely refers to the violet flower (Danish: viol) rather than the fiddle (Danish: Fiol). The section from Nørre Voldgade to Krystalgade was originally called Store Fiolstræde (Large Violet Alley) while the section from Krystalgade to Skindergade was called Lille Fiolstræde (Small Violet Alley).
Ludvig Holberg lived the last years of his life (died 1754) in a professorial residence at No. 8. The building was destroyed during the British bombardment of Copenhagen in 1807. A plaque on the wall at No. 8 commemorates the event.
The street was formerly known for its many used bookstores. Fiolstræde was pedestrianised in 1968 following the successful pedestrianisation of Strøget in the early 1960s. The narrow street (8 metres) was considered a natural second phase in the pedestrianisation of the area after the closure of Strøget in 1962.
The most notable building in the street is the former Copenhagen University Library. It was completed in 1861 to a Historicist design by Johan Daniel Herholdt.