Kentwood is a city in Kent County in the U.S. state of Michigan. The population was 54,304 as of the 2020 census. The city is bordered o…Kentwood is a city in Kent County in the U.S. state of Michigan. The population was 54,304 as of the 2020 census. The city is bordered on the northwest by Grand Rapids and is the third most-populated municipality in the Grand Rapids metropolitan area.