Justin Harvey Smith (1857, Boscawen, New Hampshire–1930, Brooklyn, New York) was an American historian and specialist on the Mexican–American War. Smith was educated at Dartmouth College (B.A. 1877; M.A. 1881) and Union Theological Seminary (1879–1881). Smith worked for Charles Scribner's Sons publishers 1881–1883 and Ginn & Co. 1883–1898 (becoming a partner in 1890); he was Professor of Modern History at Dartmouth 1899–1908. He resigned his professorship in 1908 to pursue historical research, and published The Annexation of Texas in 1911 and The War with Mexico in 1919. For the latter he received the Pulitzer Prize in 1920 and the first Loubat Prize in 1923. From 1917 to 1923 Smith was chairman of the Historical Manuscripts Commission of the American Historical Association.