Hannah Whitall Smith (1832-1911) was a lay speaker and author in the Holiness movement in the United States and the Higher Life movement in the United Kingdom of Great Britain and Ireland. She was also active in the Women's suffrage movement and the Temperance movement. Hannah Whitall Smith's book The Christian's Secret of a Happy Life (1875) is an extremely popular book of practical Holiness theology. It is still widely read today. She wrote her spiritual autobiography, The Unselfishness of God And How I Discovered It, in 1903.