Leander James McCormick (1819–1900) was an American inventor, manufacturer, philanthropist, and businessman and a member of the McCormick family of Chicago and Virginia. Along with his elder brothers Cyrus and William, he is regarded as one of the fathers of modern agriculture due to his part in the development of the McCormick Reaper and what became the International Harvester Company. He also owned and developed vast amounts of real estate in downtown Chicago and Lake Forest, Illinois.