Doctor Philastus Hurlbut (February 3, 1809 – June 16, 1883) was a 19th-century Latter Day Saint dissenter. Hurlbut is best known for his collection of affidavits which in 1834 were published in Eber D. Howe’s anti-Mormon book Mormonism Unvailed [sic]. The purpose of these affidavits was to produce damaging evidence related to the character of Joseph Smith, the founder of the Latter Day Saint movement, Smith's family, and his associates.