Walter William Spencer Cook, also known as Walter W. S. Cook in citation (7 April 1888 – 20 September 1962) was an American art historian and professor. He specialized in Spanish Medieval art history. He was an emeritus professor from New York University (working from 1926–1956) and he helped found the New York University Institute of Fine Arts. He had a prominent role in introducing eminent German art historians to the United States.