John Sadler may refer to:
John Sadler, English merchant, co-founder of the Merchant's Hope plantation, Virginia, in 1638 John Sadler (town clerk) (1615–1674), English MP, lawyer, Town Clerk of London and Master of Magdalene College, Cambridge John Sadler, English printer, inventor of transfer-printing in 1756 John Sadler (industrialist) (1820–1910), English industrialist and public servant associated with Oldbury, West Midlands John W. Sadler (born 1956), American racehorse trainer John Sadler (historian), British historian John Sadler (cricketer) (born 1981), English cricketer