Alexander Hamilton Main (June 22, 1824 – January 9, 1896) was an American businessman and politician. Born in Plainfield, New York, Main owned a store in Allegany County, New York. In 1856, Main served in the New York State Assembly, as a Republican. Main then moved to Madison, Wisconsin, in 1856, where he worked in a bank and then owned an insurance business and was president of Wisconsin Board of Underwriters. Main was also a curator of the Wisconsin Historical Society and served as the society's treasurer. He died in Madison, Wisconsin. His brother was Willett Main, who served in the Wisconsin State Senate.