- James River, Virginia, United States1
- Jeffrey, Boone County, West Virginia, United States1
- Jihocesky, Bohemia, Czech Republic1
- Johns Island, Charleston County, South Carolina, United States1
- Jonesville, Union County, South Carolina, United States1
- Joplin, Jasper County, Missouri, United States1
- Juan de la Chico Mine, Guanajuato, Mexico1
- Jumilla, Murcia, Spain1
- Kansas City, Jackson County, Missouri, United States1
- Kaskaskia River, Illinois, United States1
- Kelleys Island, Erie County, Ohio, United States1
- Kentucky River, Frankfort,Kentucky, United States1
- Kershaw, Lancaster County, South Carolina, United States1
- Keweenaw Point, Keweenaw County, Michigan, United States1
- Key Biscayne, Dade County, Florida, United States1
- Key West, Monroe County, Florida1
- Kings Creek District, Cherokee County, South Carolina, United States1
- Kingstree, Williamsburg County, South Carolina, United States1
- La Rochelle, Charente-Maritime department, France1
- Labrador, Newfoundland and Labrador, Canada1