Benét graduated from Stanford University in 1935.[1] He worked at The New Republic after college, before going to Spain to fight with the Abraham Lincoln Brigade.[1] He was a brigade combat soldier and ambulance driver from 1936 to 1937, later leaving Spain when the war turned in favor of Francisco Franco.[1] In a 2012 interview with Public Radio International, Benét explained his reasoning for joining the war, "If the moment comes when it's the obvious right thing and somebody's got to do it, maybe it's going to be you...I always felt that I was on the right side of history in Spain."[1]
Benét joined the staff of the San Francisco Chronicle in 1947 as a copy editor.[1] He was soon subpoenaed by the House Un-American Activities Committee in Washington D.C., who wanted information on his time in Spain during the war.[1] While Benét appeared before the committee, he refused to their questions, a position supported by his superiors at the San Francisco Chronicle. The House Un-American Activities Committee ultimately took no action against Benét.[1]
James Benét was married three times. He and his first wife, actress Mary Liles, divorced.[1] He then married Jane Gugel, the San Francisco Chroniclefood editor and columnist who wrote under the pen name "Jane Friendly."[1] Following Gugel's death, Benét married her sister-in-law, Ruth Gugel, who later died, leaving him a widower.[1]