Harry Leland Mitchell was an American union leader. He was a cofounder and leader of the Southern Tenant Farmers Union (STFU) in 1934, and led its successor unions, for most of the next twenty-six years. He had been a sharecropper himself, and a socialist like his fellow instigator of the STFU, Clay East. They led an initially small racially mixed union of poor people within three years to a membership of some 30,000 tenant farmers and sharecroppers. As the STFU evolved through association with larger, more powerful unions, it changed its name, and Mitchell his official role. He was President of the National Farm Labor Union (NFLU), then of the National Agricultural Workers Union (NAWU), before retiring in 1960. In 1979, he published a memoir concerned almost entirely with his organizing activities.

The Southern Tenant Farmers Union (STFU) (1934–1960) was founded as a civil farmer's union to organize tenant farmers in the Southern United States. Many such tenant farmer sharecroppers were Black descendants of former slaves.