Gavin Arthur (born Chester Alan Arthur III; March 21, 1901 – April 28, 1972) was a San Francisco astrologer and sexologist and a grandson of American President Chester A. Arthur.
He has been described as "an Ivy League dropout, an Irish Republican Army activist, an experimental-film actor, a commune leader, a gold prospector, a teacher at San Quentin, and a bisexual sexologist/astrologer. An early gay rights activist and a practical prototype for the hippies."
Arthur was born in Colorado Springs, Colorado in 1901 to Chester Alan Arthur II and his wife, Myra Townsend Fithian Andrews. He was their only child. Arthur's father's part-ownership of a mining and ranching company gave the family a comfortable living. Arthur attended Columbia University, but did not graduate. After leaving school he married Charlotte Wilson in 1922; they were divorced ten years later.
After leaving college, Arthur worked in the Irish Republican Movement, living in New York, France, and Ireland. He was once jailed in Boston in connection with the movement. While in Europe, Arthur and Charlotte had roles in the 1930 avant-garde film, Borderline, which also starred Paul Robeson and H.D. In the early 1930s he moved to Pismo Beach, California, and adopted the name "Gavin," by which he would be known for the rest of his life. While there, Arthur founded an art and literature commune and published a short-lived magazine, Dune Forum. In 1934, he joined the Utopian Society of America. The following year, he married Esther Murphy Strachey.
Eschewing the Republican Party of his grandfather, Arthur served as secretary of the California Democratic Party in 1940 before resigning the following year, convinced that the party had betrayed his principles. At the outbreak of World War II, Arthur enlisted in the United States Navy.