| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Jackson | city | Iowa | United States | 42.15 | -91.35 | 853 | |
| Jackson Junction | city | Iowa | United States | 43.11 | -92.03 | 1148 | |
| Jacksonville | city | Iowa | United States | 41.65 | -95.15 | 1669 | |
| Jacksonville | city | Iowa | United States | 43.12 | -92.21 | 1151 | |
| Jacksonville (historical) | city | Iowa | United States | 41.11 | -93.56 | 1049 | |
| Jacobs | city | Iowa | United States | 41.66 | -92.67 | 997 | |
| Jamaica | city | Iowa | United States | 41.85 | -94.31 | 1036 | |
| James | city | Iowa | United States | 42.58 | -96.32 | 1138 | |
| Jamestown | city | Iowa | United States | 41.49 | -90.71 | 830 | |
| Jamestown | city | Iowa | United States | 41.43 | -92.35 | 902 | |
| Jamison | city | Iowa | United States | 41.12 | -93.72 | 1000 | |
| Janesville | city | Iowa | United States | 42.65 | -92.46 | 889 | |
| Jay | city | Iowa | United States | 41.11 | -93.59 | 1049 | |
| Jefferson | city | Iowa | United States | 42.02 | -94.38 | 1076 | |
| Jeffersonville (historical) | city | Iowa | United States | 40.61 | -91.45 | 830 | |
| Jerico | city | Iowa | United States | 43.18 | -92.26 | 1171 | |
| Jerome | city | Iowa | United States | 40.72 | -93.03 | 1000 | |
| Jesup | city | Iowa | United States | 42.48 | -92.06 | 974 | |
| Jewell | city | Iowa | United States | 42.31 | -93.64 | 1062 | |
| Johnson (historical) | city | Iowa | United States | 42.15 | -91.03 | 830 | |
| Johnston | city | Iowa | United States | 41.67 | -93.70 | 830 | |
| Joice | city | Iowa | United States | 43.36 | -93.45 | 1249 | |
| Jolley | city | Iowa | United States | 42.48 | -94.72 | 1223 | |
| Jones Siding | city | Iowa | United States | 42.68 | -94.21 | 1069 | |
| Jordan | city | Iowa | United States | 42.05 | -93.78 | 1099 | |
| Jordans Grove | city | Iowa | United States | 42.16 | -91.50 | 958 | |
| Jubilee | city | Iowa | United States | 42.38 | -92.10 | 905 | |
| Judd | city | Iowa | United States | 42.47 | -94.05 | 1108 | |
| Julien | city | Iowa | United States | 42.48 | -90.78 | 885 | |
| Junction (historical) | city | Iowa | United States | 43.09 | -91.63 | 1085 | |
| Junction Switch | city | Iowa | United States | 42.28 | -91.20 | 839 | |
| Juniata | city | Iowa | United States | 42.58 | -95.15 | 1669 |