The son of a yeoman with an annual income of £40, Selden left an estate of £ 50,000, a library of more than eight thousand volumes, and a collection of Greek sculptures and monuments. His reputation was so distinguished that Archbishop James Ussher came out of retirement to preach the sermon at his funeral, which was attended by "all the judges and other persons of distinction" in the Temple Church, where his gravestone lies in the floor near the south porch.

Selden was a dedicated researcher and a prolific writer, a biblical scholar, a famous orientalist, and a practical philosopher. He was also a first-rate historian and one of the leading antiquaries of his day. In Areopagitica (1644) John Milton called him "the chief of learned men reputed in this land." Ben Jonson, a friend of Selden's youth, described him as "the law-book of the judges of England, the bravest man in...