Plainfield is the name of several places
In Canada:
- Plainfield, Ontario
In the United States:
- Plainfield, California
- Plainfield, Connecticut
- Plainfield Village, Connecticut
- Plainfield, Illinois
- Plainfield, Indiana, a town in Hendricks County
- Plainfield, LaPorte County, Indiana, an unincorporated community
- Plainfield, Iowa
- Plainfield, Massachusetts
- Plainfield, New Hampshire
- Plainfield, New Jersey
- Plainfield, New York
- Plainfield, Ohio
- Plainfield, Pennsylvania
- Plainfield, Vermont
- Plainfield (town), Wisconsin
- Plainfield, Wisconsin, a village mostly within the town
- Plainfield Township, Kent County, Michigan
- Plainfield Township, Iosco County, Michigan
- Plainfield Township, Northampton County, Pennsylvania