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.
He 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, "I suppose I was what the Party called a 'member at large.'"