The LSE Library (British Library of Political and Economic Science) was founded in 1896 by Beatrice and Sidney Webb, founders of LSE. It is a Library for LSE and a resource for social science researchers. It is one of the largest social science Libraries in the world. It moved to its current location – the Lionel Robbins Building – in 1978. This building was redeveloped by the architects Foster and Partners and was completed in 2001.

The Library holds over 4 million books and journals. It collects comprehensively in economics and other core social sciences and contains material in the major European languages. Special collections include government publications, the publications of intergovernmental organisations, historical pamphlets, statistics and there is a substantial archive collection. Archives include those of the Fabian Society, the Liberal Party, papers of individual politicians and the Hall Carpenter Archives, focussing on the history of LGBTQ+ activism in the UK. All collections held at LSE in the Library have been recognised for their outstanding national and international importance and awarded 'Designation' status by the Museums Libraries and Archives Council (MLA).

Online resources developed and maintained by the Library include LSE Digital Library, an archive of digitised and born digital collections, and Charles Booth's London, focusing on the work of Booth’s pioneering team of social researchers and making available his famous poverty maps. Further information about the Library’s physical and digital collections can be found on the Library’s Collection Highlights pages