Ralph Wilmer Thomas (June 11, 1862 in Cornwallis, Kings County, Nova Scotia, Canada – March 25, 1920) was an American politician, author, professor and librarian from New York.
He graduated from Colgate University, then called Madison University, in 1883. He studied Law at the University of Albany and English at Columbia University. He taught English at The Albany Academy from 1883-1887.
He was admitted to the bar in 1885, but continued to teach, and was an examiner for the Board of Regents of the University of the State of New York. He was Chief Examiner from 1889 to 1892.
In 1891, he married Effie Southwick, a sister of Congressman George N. Southwick (1863–1912). They had one child, Margaret Julia (who married Alfred Waters I), and one grandson, Ralph Thomas Waters I.
He was Professor of Rhetoric and Public Speaking at Colgate University from 1893 to 1913. During that time he also served as Registrar of the University from 1892 to 1905, and Librarian from 1892 to 1908. In 1903, he was appointed as a member of the New York State Board of Charities.
Thomas was elected on April 28, 1910, to the New York State Senate (37th D.) to fill the vacancy caused by the resignation of Jotham P. Allds, and attended the last weeks of the regular session, and the special session, of the 133rd New York State Legislature. He was re-elected twice, and sat in the 134th, 135th, 136th and 137th New York State Legislatures until 1914.