The British Library is a research library in London that is the national library of the United Kingdom. It is one of the largest libraries in the world. It is estimated to contain between 170 and 200 million items from many countries. As a legal deposit library, the British Library receives copies of all books produced in the United Kingdom and Ireland, including a significant proportion of overseas titles distributed in the UK. The Library is a non-departmental public body sponsored by the Department for Culture, Media and Sport.

The British Library is a major research library, with items in many languages and in many formats, both print and digital: books, manuscripts, journals, newspapers, magazines, sound and music recordings, videos, play scripts, patents, databases, maps, stamps, prints, and drawings. The Library’s collections include around 14 million books and substantial holdings of manuscripts and items dating as far back as 2000 BC. The library maintains a program for content acquisition and adds three million items each year occupying 9.6 kilometres (6 mi) of new shelf space.