Thomas Marion Eaton (born August 3, 1896) was a Republican member of the United States House of Representatives from California. He represented California’s 18th Congressional District during the Seventy-sixth Congress. His tenure in federal office began on January 3, 1939, and concluded on January 3, 1941, encompassing a single term in the House.

Serving as a Representative from California, Eaton participated in national legislative affairs at the end of the 1930s, a period marked by significant domestic and international developments. Although specific committee assignments, legislative initiatives, and subsequent career details are not provided in the available record, his service as a one-term Republican congressman places him among the historical members of Congress who contributed to the representation of California’s 18th District during this era.