Parley Parker Pratt, Sr. (April 12, 1807 – May 13, 1857) was an early leader of the Latter Day Saint movement whose writings became a significant early nineteenth-century exposition of the Latter Day Saint faith. Named in 1835 as one of the first members of the Quorum of the Twelve Apostles, Pratt was part of the Quorum's successful mission to Great Britain from 1839 to 1841. Pratt has been called "the Apostle Paul of Mormonism" for his promotion of distinctive Mormon doctrines.