The Reykjavík City Library, originally called the Public Library and later the Municipal Library, opened its door to the public in Reykjavík the first of April 1923. The museum was founded by the Town Council in Reykjavík on November 18, 1920.
The Library was originally located on Skólavörðustígur 3, where it was sited in only three rooms. Five years after the opening, the Library moved to a bigger place in Ingólfsstræti 12, rented by the City Council. In 1950 the house at Þingholtsstræti 29A was purchased for the library. This former residence build in 1916 soon became too small for its current purpose and the hunt for bigger place for the library begun. The library is now situated in Tryggvagata 15 in the city center with its main branch and is in five other neighborhoods around the city.