Thomas Marion Eaton (August 3, 1896 – September 16, 1939) was an American businessman and World War I veteran who served briefly as a U.S. Representative from California in 1939.

He moved to Long Beach, California, in 1921 and engaged in the automobile sales business.

Eaton was elected as a Republican to the Seventy-sixth Congress and served from January 3, 1939, until his death in Long Beach, California, September 16, 1939.

Eaton's seat remained vacant until his elected successor, William Ward Johnson, took office in January 1941.

This article incorporates public domain material from the Biographical Directory of the United States Congress