Thomas Fearn (November 15, 1789 – January 16, 1863) was an American physician, businessman, and politician who played a significant role in the early development of Huntsville, Alabama.

[1][2] Fearn is credited with discovering the medicinal properties of quinine for treating malaria, which became a significant advancement in the prevention and treatment of the disease.

By 1860, he was one of the largest slaveholders in Madison County, owning 82 enslaved people, whom he used for both agricultural labor and public works projects.

In 1862, he was arrested by federal forces for refusing to swear allegiance to the United States but was later released due to his failing health.

[2][1] Fearn is remembered as an influential figure in the development of Huntsville and as a pioneer in medical practices related to malaria treatment.