Gratiot County is a county in the U.S. state of Michigan. As of the 2020 Census, the population was 41,761. The county seat is Ithaca, although its most populous city is Alma.

The Territory of Michigan was an organized incorporated territory of the United States that existed from June 30, 1805, until January 26, 1837, when the final extent of the territory was admitted to the Union as the State of Michigan. Detroit was the territorial capital.