On 21 December 1918, the Provisional Government of the Estonian Republic took the decision to establish the State Library. The primary collection of the library was about 2000 titles necessary for lawmaking and government. The library was situated in two small rooms of Toompea Castle, the Parliament building.
In the time of the independent Republic of Estonia the library developed and grew quickly. In the summer of 1919, the library began to receive a legal deposit copy of all printed matter published in Estonia. The first foreign exchange agreements were made in 1921. In 1935 Estonia celebrated the 400th anniversary of the first book in Estonian known at that time - a catechism by Wanradt-Koell. The same year saw the founding of the Mandatory Deposit Collection of Estonian Printed Matter and the systematic acquisition of literature concerning Estonia and the Baltics began. By the end of the 1930's the State Library had become much more than a government library. The number of items in the collection reached about 50 000 and the readership included several outstanding intellectuals, cultural, and public figures.
With the Soviet occupation, the library became a regular public library (1944), run in conformity with Soviet library regulations. The library work underwent profound changes: all links with foreign libraries were severed, and Russian publications predominated, the majority of it constituting Soviet legal deposit copies. The bulk of Estonian publications was placed in restricted access collections.
In 1953, the State Library was named after Friedrich Reinhold Kreutzwald, an outstanding public figure of the National Awakening Period of Estonia and author of the Estonian national epic poem "Kalevipoeg". By 1953, the collection of the library had already reached a million items.
The liberation movement that began in the Baltic countries in the second half of the 1980's as well as the restoration of the independent Republic of Estonia on August 20, 1991 considerably changed the role of the library. In 1988, Fr. R. Kreutzwald State Library was renamed the National Library of Estonia with its aim to collect, permanently preserve and make publicly accessible documents published in the Estonian language and in Estonia as well as concerning Estonia or including information about Estonia. In 1989, the National Library of Estonia regained its status as a parliamentary library responsible for serving the information needs of Parliament and Government.
Today, the National Library of Estonia is a legal person in public law who operates pursuant to the National Library of Estonia Act, passed by the Riigikogu in 1998 and amended in 2002, and the Articles of Association. The collegial decision-making power is vested in the Supervisory Board of the National Library, appointed by the Riigikogu.