John Hancock Klippart (1823-1878) was an American agriculturist and expert on wheat farming.
Klippart was born in Stark County, Ohio. Klippart worked for the Ohio State Board of Agriculture and has been described as the most "informed individual" of his time on wheat culture. He published a large book in 1858 documenting information about wheat plants and farming.
Klippart was an early evolutionary thinker to have mentioned the concept of natural selection. According to science historian Conway Zirkle "In 1858, Klippart showed how nature could displace one variety or species of wheat by another."