Isaac Newton Seligman (July 10, 1855 – September 30, 1917) was an American banker and communal worker. In 1878, after a two-year apprenticeship in the firm of Seligman & Hellman in New Orleans, he joined the New York branch, of which he became head in 1885, on the death of his father Joseph Seligman and his brother.
He was connected with almost all the important social reform committees in New York. He was a trustee of institutions and societies, including the Munich Life Assurance Company, St. John's Guild, and the McKinley Memorial Association. He was a member of the Committee of Seventy, of Fifteen, and of Nine, each of which attempted at various times to reform municipal government in New York; of the last-named body he was chairman. He was a trustee of Temple Emanu-El and of the Hebrew Orphan Asylum, as well as of the United Hebrew Charities, and also a member of the Ethical Culture Society. He was married to Guta Loeb (1865–1956), daughter of banker Solomon Loeb.
