William Sloane Coffin Jr. (June 1, 1924 – April 12, 2006) was an American Christian clergyman and long-time peace activist.
He was ordained in the Presbyterian church and later received ministerial standing in the United Church of Christ.
In his younger days he was an athlete, a talented pianist, a CIA agent, and later chaplain of Yale University, where the influence of Reinhold Niebuhr’s social philosophy led him to become a leader in the Civil Rights Movement and peace movements of the 1960s and 1970s. He also was a member of the secret society Skull and Bones. He went on to serve as Senior Minister at the Riverside Church in New York City and President of SANE/Freeze (now Peace Action), the nation’s largest peace and justice group, and prominently opposed United States military interventions in conflicts such as the Vietnam War to the Iraq War. He was also an ardent supporter of gay rights.