Hannah Tatum Whitall Smith is an American lay speaker and author in the Holiness movement in the United States and the Higher Life movement in the United Kingdom. She was also active in the women's suffrage movement and the temperance movement.

Born in Philadelphia, Smith was from a long line of prominent and influential Quakers in New Jersey. Hannah Tatum Whitall was the daughter of John Mickle Whitall and Mary Tatum Whitall. Her most famous ancestor was Ann Cooper Whitall.

On November 5, 1851 Hannah married Robert Pearsall Smith, a man who also descended from a long line of prominent Quakers in the region. The Smiths settled in Germantown, Pennsylvania. They disassociated themselves somewhat from the Quakers in 1858 after a conversion experience, but Mrs. Smith continued to believe a great deal of Quaker doctrine and gloried in her Quaker background and practices. The Smiths were highly influenced firstly by the Plymouth Brethren, and then by the Methodist revivalists. Out of influence from the Wesleyan doctrine of sanctification, and in accordance with Quaker teaching and influences from spiritualism, Mrs. Smith and her husband formulated and promulgated the Keswick theology. They were also influenced by William Boardman, who wrote The Higher Christian Life (1858).