John O. Thomas was an American politician. He was a member of the Wisconsin State Assembly.
Thomas was born on November 23, 1867, in Caledonia, Wisconsin.[1] He would become a farmer there. Thomas was affiliated with Presbyterianism. He died on February 2, 1961.
Thomas was elected to the Assembly in 1904 and 1906. Previously, he had been town clerk of Caledonia, now a village, from 1896 to 1899. He was a Republican.[2]