DeWitt is a city in Clinton County in the U.S. state of Michigan. The population was 4,776 at the 2020 census. The city is located north of …DeWitt is a city in Clinton County in the U.S. state of Michigan. The population was 4,776 at the 2020 census. The city is located north of Interstate 69 and west of U.S. Route 127, just north of the city of Lansing.