Louis S. Cox (November 22, 1874 – May 12, 1961) was a justice of the Massachusetts Supreme Judicial Court from November 10, 1937, to January 12, 1944. He was appointed by Governor Charles F. Hurley. Born in Manchester, New Hampshire, Cox was one of four brothers including Channing H. Cox, who became Governor of Massachusetts. Cox received a B.A. from Dartmouth College in 1896, and a law degree from Boston University School of Law in 1899. In 1904, he was elected to represent Lawrence, Massachusetts in the Massachusetts Senate, and in 1906 was appointed as a postmaster by President Theodore Roosevelt. In 1915, Cox was elected Essex County District Attorney, which office he held until 1918, when Governor Samuel W. McCall appointed Cox to the Massachusetts Superior Court. In 1937, Governor Ch