What is now Brunswick Square was originally fields that were part of the grounds of the Foundling Hospital. It was planned to be leased for housebuilding, along with Mecklenburgh Square, to raise funds for the hospital in 1790. Brunswick Square, named after Caroline of Brunswick, was finished first, being built by James Burton in 1795–1802; none of the houses remain.
Leafy squares characterise the Bloomsbury district of London. Mecklenburgh Square is a matching square to the east. Russell Square is the nearest tube station to the south-west.
In Jane Austen's book Emma, the characters of Mr. and Mrs. John Knightley make their residence in Brunswick Square.
The writer E.M. Forster used 26 Brunswick Square as his London base from 1930 to 1939.