Plainfield is a village in Will and Kendall counties, Illinois, United States. The population was 44,762 at the 2020 census. The village includes land in Will County's Plainfield and Wheatland townships, as well as Na-Au-Say and Oswego townships in Kendall County. With the growth in the Chicago suburbs in the 1990s and 2000s, the village has seen a population increase, from 4,500 in 1990 to 28,000 in 2000 to nearly 45,000 in 2016. It is between the cities of Naperville and Joliet.