John Sadler
John Sadler may refer to:
- John Sadler, English merchant, co-founder of the Merchant's Hope plantation, Virginia, in 1638
- John Sadler (town clerk), 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), English industrialist and public servant associated with Oldbury, West Midlands
- John W. Sadler, American racehorse trainer
- John Sadler (historian), British historian
- John Sadler (cricketer), English cricketer