The Wellcome Library is a free library and Museum based in central London. It was developed from the collection formed by Sir Henry Wellcome (1853–1936), whose personal wealth allowed him to create one of the most ambitious collections of the 20th century. Henry Wellcome's interest was the history of medicine in a broad sense and included subjects such as alchemy or witchcraft, but also anthropology and ethnography. Since Henry Wellcome's death in 1936, the Wellcome Trust has been responsible for maintaining the Library's collection and funding its acquisitions. The library is free and open to the public.

Sir Henry Solomon Wellcome was an American pharmaceutical entrepreneur. He founded the pharmaceutical company Burroughs Wellcome & Company with his colleague Silas Burroughs in 1880, which is one of the four large companies to eventually merge to form GlaxoSmithKline. He left a large amount of capital for charitable work in his will, which was used to form the Wellcome Trust, one of the world's largest medical charities. He was a keen collector of medical artefacts which are now managed by the Science Museum, London, and a small selection of which are displayed at the Wellcome Collection.