The Joint Committee of the Legislative Council and the House of Assembly established the New Brunswick Legislative Library in 1841. This action formalized the library's creation, which had taken place in 1784 when the province was formed. During most of the 19th century, the library was located in Province Hall, the original legislative building. It is now located in the present Legislative Assembly Building which was erected during the period 1880-1882.
For much of the period up to 1955 the Legislative Library also provided public library service. In 1955 the responsibility for public library service was transferred to the now New Brunswick Public Library Service. The Legislative Library Act of 1976 formalized the Legislative Library's primary service to the Members of the Legislative Assembly.
New Brunswick's first parliamentary librarian, Mark Needham, was appointed in 1842.