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
{{Human name disambiguation, Sadler, John