Frederick Vanderbilt Field (April 13, 1905 – February 1, 2000) was an American leftist political activist and a great-great-grandson of railroad tycoon Cornelius "Commodore" Vanderbilt, disinherited by his wealthy relatives for his radical political views. Field became a specialist on Asia and was a prime staff member and supporter of the Institute of Pacific Relations. He also supported Henry Wallace's Progressive Party and so many openly Communist organizations that he was accused of being a member of the Communist Party, and was a top target of the American government during the peak of 1950s McCarthyism. Field denied ever having been a party member, but admitted in his memoirs that "I suppose I was what the Party called a 'member at large.'"