Plainfield
- Plainfield (CDP), New Hampshire
- Plainfield (CDP), Vermont
- Plainfield (soil)
- Plainfield (town), Wisconsin
- Plainfield Academy (disambiguation)
- Plainfield High School (disambiguation)
- Plainfield Township (disambiguation)
- Plainfield Village, Connecticut
- Plainfield, California
- Plainfield, Connecticut
- Plainfield, Georgia
- Plainfield, Illinois
- Plainfield, Indiana
- Plainfield, Iowa
- Plainfield, Massachusetts
- Plainfield, Michigan (disambiguation)
- Plainfield, New Hampshire
- Plainfield, New Jersey
- Plainfield, New York
- Plainfield, Ohio
- Plainfield, Ontario
- Plainfield, Pennsylvania
- Plainfield, St. Joseph County, Indiana
- Plainfield, Vermont
- Plainfield, Wisconsin