Glenn Smiley (April 19, 1910 – September 14, 1993) was a white civil rights consultant and leader. He closely studied the doctrine of Mahatma Gandhi and became convinced that racism and segregation were most likely to be overcome without the use of violence, and began studying and teaching peaceful tactics. As an employee of the Fellowship of Reconciliation (FOR), he visited Martin Luther King, Jr. in Montgomery, Alabama in 1956 during the Montgomery bus boycott where Smiley advised King and his associates on nonviolent tactics, and was able to convince King that nonviolence was a feasible solution to racial tension. Smiley, together with Bayard Rustin and others, helped convince King and his associates that complete nonviolence and nonviolent direct action were the most effective methods and tools to use during protest. After the Civil Rights Movement, Smiley continued to employ nonviolence and worked for several organizations promoting peace in South American countries. Just three years before him 1993 death, Smiley opened the King Center in Los Angeles.
During his work in ministry in the 1940s, Smiley developed an interest for the methods of Mahatma Gandhi and his methods of self-discipline and nonviolence. From these studies, he developed his theory that nonviolence was the most effective way to combat discrimination. Smiley first used his theory of nonviolence in the late 1940s when he attempted to spur integration of tearooms of department stores in the Los Angeles area. Smiley went on to have a professional relationship with Martin Luther King, in which he advised King on nonviolence tactics and emphasized the importance of nonviolence in the success of the Civil Rights Movement. Smiley was already impress with Dr. King's leadership, but was critical of King for having a bodyguard. In a letter that Smiley had written to some of his friends, he was quoted writing, "If King can really be won to a faith of nonviolence there is no end to what he can do. Soon he will be able to direct movement by sheer force of being the symbol of resistance. Smiley also persuaded King that there needs to be an active dialogue between the white and black ministers in the South. King sent Smiley around the South preaching the doctrine to church congregations and civil-rights groups, and nonviolence quickly became a binding premise of King's Southern Christian Leadership Conference.