David Whitmer (January 7, 1805 - January 25, 1888) was one of the original six members of The Church of Christ (the original name of the church from which the current Church of Jesus Christ of Latter-day Saints, colloquially known as the Mormon Church, traces its origin) and one of the witnesses to the Book of Mormon.
A close friend of Joseph Smith, Jr., he was later excommunicated from the Church in 1838.
In 1887, he published An Address to All Believers in Christ, in which he reaffirmed his original testimony and his belief that the Book of Mormon was the word of God, but asserted that the Church which had been established by Joseph Smith, had subsequently "drifted into error".
He died the following year in Richmond, Missouri.