The 1858 New York state election was held on November 2, 1858, to elect the governor, the lieutenant governor, a Canal Commissioner, and an Inspector of State Prisons, as well as all members of the New York State Assembly and two members of the New York State Senate. Besides, the question was asked if a Constitutional Convention should be held, and answered in the negative: The vote was 135,266 for and 144,526 against.

Edwin Denison Morgan was the 21st governor of New York from 1859 to 1862 and served in the United States Senate from 1863 to 1869. He was the first and longest-serving chairman of the Republican National Committee. He was also a Union Army general during the American Civil War. Morgan was known for his progressive views on education, prison reform, and women's suffrage. He helped to found the Republican Party in New York and was a strong supporter of the Presidency of Abraham Lincoln.