William Lilly (1602–1681) was an English astrologer and occultist.
William Lilly may refer to: William Lilly (politician) (1821–1893), American politician William Lily (grammarian) (1468–1522), English scholar and Latin grammarian William Samuel Lilly (1840–1919), English barrister and writer William Liley (1929–1983), New Zealand surgeon and perinatal physiologist