The Morrill Tariff was an increased import tariff in the United States that was adopted on March 2, 1861, during the administration of US President James Buchanan, a Democrat. It was the twelfth of the seventeen planks in the platform of the incoming Republican Party, which had not yet been inaugurated, and the tariff appealed to industrialists and factory workers as a way to foster rapid industrial growth.

Justin Smith Morrill was an American politician and entrepreneur who represented Vermont in the United States House of Representatives (1855–1867) and United States Senate (1867–1898). He is most widely remembered for the Morrill Land-Grant Acts that provided federal funding for establishing many of the United States' public colleges and universities. Originally a Whig, after that party became defunct Morrill was one of the founders of the Republican Party.