After one year at New Orleans' Dillard University, in 1947 Young went to Howard University in Washington D.C where he received his Bachelor of Science and pre-med degree in 1951. He had originally planned to follow his father's career of dentistry, but then felt a religious calling. He entered the ministry and received a Bachelor of Divinity degree from Hartford Theological Seminary in Hartford, Connecticut in 1955.
Andrew Young then served as pastor of a church in Marion, Alabama. In Marion he met Jean Childs, who was to become his wife, and studied the writings of Mohandas Gandhi. Young became interested in Gandhi's concept of non-violent resistance as a tactic for social change. He encouraged African Americans to register to vote in Alabama, sometimes facing death threats while doing so. He became a friend and ally of Dr. Martin Luther King at this time.
In 1957 moved to New York City to accept a job with the National Council of Churches. However as the civil rights movement heated up Young decided that his place was back in the US South, and moved to Atlanta, Georgia. He again worked on drives to register Black voters. In 1964 he was named executive director of the Southern Christian Leadership Conference, with whom he organized many peaceful protests. Young became one of Dr. King's principle lieutenants, and was with King in Memphis, Tennessee when King was shot in 1968.
In 1976, President Jimmy Carter appointed Young the U.S ambassador to the United Nations. He held that post until 1979, when he was forced to resign after a controversy ignited over his meeting with a representative of the Palestinian Liberation Organization..
Young was co-chair of the committee which brought the 1996 Summer Olympics to Atlanta.
Young continues his activism in favor of human rights, and is co-chair of Good Works International.