William Ponsonby (1546? – 1604) was a prominent London publisher of the Elizabethan era. Active in the 1577–1603 period, Ponsonby published the works of Edmund Spenser, Sir Philip Sidney, and other members of the Sidney circle; he has been called "the leading literary publisher of Elizabethan times." Ponsonby completed his apprenticeship under stationer William Norton on 11 January 1571. Around 1576 he established his own bookshop at the sign of the Bishop's Head in St. Paul's Churchyard. On Ponsonby's death in 1604, many of his copyrights passed to his brother-in-law, stationer Simon Waterson.