Chester Alan "Gavin" Arthur III was an American astrologer and sexologist. He was the grandson of Chester A. Arthur, the twenty-first president of the United States. He received his early education from Columbia College and later joined the Philolexian Society. He left his college and participated in the Irish Republican Movement. During his time in Ireland, he began going by the name Gavin.

Labor Defender (1926–1937) was a magazine published by the International Labor Defense (ILD), itself a legal advocacy organization established in 1925 as the American section of the Comintern's International Red Aid network and thus as support to the Communist Party.