Warren Joseph Duffey (January 24, 1886 – July 7, 1936) was a U.S. Representative from Ohio.
Born in Toledo, Ohio, Duffey attended the public schools.
Duffey graduated from St. John's University in Toledo, Ohio, in 1908 and from the law department of the University of Michigan at Ann Arbor in 1911. Duffey was admitted to the bar the same year and commenced the practice of law in Toledo, Ohio.
Duffey served in the Ohio House of Representatives in 1913 and 1914 and as a member of the Toledo City Council in 1917 and 1918. He served as chairman of the Lucas County Democratic central committee from 1919 and 1932 and was a delegate to the 1932 Democratic National Convention.
Duffey was elected as a Democrat to the Seventy-third and Seventy-fourth Congresses and served from March 4, 1933, until his death. He was an unsuccessful candidate for renomination in 1936.
Duffey died in Toledo, Ohio on July 7, 1936. He is interred in Calvary Cemetery.