Horatio Seymour (May 31, 1810 – February 12, 1886) is an American politician.
He is the 18th Governor of New York from 1853 to 1854 and from 1863 to 1864.
He is the Democratic Party nominee for president of the United States in the presidential election of 1868, but loses the election to Republican and former Union General of the Army Ulysses S. Grant.