Thomas T. Duffy was a member of the Wisconsin State Assembly.
Duffy was born on December 6, 1835, in New York City. He moved to Benton, Wisconsin, in 1855 and graduated from Sinsinawa Mound College in 1858.
Duffy was elected to the Assembly in 1869. Previously, he was Treasurer of Benton and a justice of the peace in 1868. He was a Democrat.