Thomas Allen (August 29, 1813 – April 8, 1882)[1] was an American railroad builder and a member of the United States House of Representatives from Missouri.

His father-in-law, William Russell, gave him land in south St. Louis, which he developed as residential property attractive for working-class immigrants.

With his political connections, he arranged for loan guarantees and land grants that helped to start the company.

After an unsuccessful run for Congress in 1862, he returned to the railroad business in 1867 with the St. Louis, Iron Mountain and Southern Railway.

He was the founder of the Allen professorship of Mining and Metallurgy at Washington University in St. Louis and in 1876 he donated the Berkshire Athenaeum to his hometown of Pittsfield, Massachusetts.