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 left the Quakers in 1858 after undergoing a Christian conversion .The Smiths were highly influenced firstly by the Plymouth Brethren, and then by the Methodist revivalists. They adopted the Wesleyan doctrine of sanctification. They were also influenced by William E. Boardman, who wrote The Higher Christian Life (1858).

From 1864 to 1868 Robert and Hannah Smith lived in Millville, New Jersey. Robert managed Hannah’s father’s business, the Whitall, Tatum & Company glass factories.

William Boardman apparently groomed Robert and Hannah Smith to join the Holiness movement as speakers. From 1873–1874 they spoke at various places in England, including Oxford, teaching on the subjects of the "higher life" and "holiness." In 1874 Hannah helped found the Women’s Christian Temperance Union. That same year the Smiths traveled to the German Empire and Switzerland, where they preached in several major cities. In 1875, they returned to England and conducted meetings in Brighton. Due to a sexual scandal involving Robert, their visit to England came to an abrupt halt, with Hannah never becoming totally reconciled with her husband thereafter.

In 1888, the Smith family moved to England because their daughter Mary married an English barrister, Frank Costelloe. They eventually divorced, and Mary then married the critic Bernard Berenson. It was in England that Alys Pearsall Smith met and married the philosopher Bertrand Russell. Logan Pearsall Smith became an essayist and critic.

Hannah Whitall Smith had seven children in all, but only three—Mary, Alys Pearsall, and Logan Pearsall—survived to adulthood. Her niece, Martha Carey Thomas was the first female dean of any college in America and an active Suffragist.

Hannah Whitall Smith died in England in 1911.

Hannah Whitall Smith’s book The Christian’s Secret of a Happy Life (1875) is an extremely popular book of Christian principles and 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. Many publications of that book omit the three chapters which explain how she became a Christian universalist. The Unselfishness of God and How I Discovered It (the missing chapters) at www.tentmaker.org