| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Opa-locka | city | Florida | United States | 25.90 | -80.25 | 6 | |
| Opaeopaeilio | city | Hawaii | United States | 22.02 | -159.42 | 830 | |
| Opah | city | Oklahoma | United States | 36.75 | -96.29 | 898 | |
| Opal | city | Arkansas | United States | 35.10 | -92.00 | 259 | |
| Opal | city | Arkansas | United States | 34.54 | -93.99 | 898 | |
| Opal | city | Missouri | United States | 37.02 | -93.77 | 1669 | |
| Opal | city | South Dakota | United States | 44.89 | -102.45 | 2614 | |
| Opal | city | Virginia | United States | 38.62 | -77.80 | 830 | |
| Opal | city | West Virginia | United States | 38.39 | -80.77 | 2089 | |
| Opal | city | Wyoming | United States | 41.77 | -110.33 | 6709 | |
| Opal City | city | Oregon | United States | 44.44 | -121.21 | 2811 | |
| Opal Cliff Park Mobile Home Park | city | California | United States | 36.96 | -121.97 | 29 | |
| Opal Cliffs | city | California | United States | 36.96 | -121.96 | 0 | |
| Opdyke | city | Illinois | United States | 38.26 | -88.79 | 830 | |
| Opdyke | city | Texas | United States | 33.59 | -102.28 | 3418 | |
| Opdyke West | city | Texas | United States | 33.59 | -102.30 | 3444 | |
| Opegoi (historical) | city | California | United States | 41.26 | -123.61 | 1013 | |
| Opekiska | city | West Virginia | United States | 39.56 | -80.06 | 1069 | |
| Opeleika (historical) | city | Georgia | United States | 34.98 | -85.14 | 830 | |
| Opelika | city | Alabama | United States | 32.65 | -85.38 | 830 | |
| Opelika | city | Texas | United States | 32.30 | -95.67 | 396 | |
| Opelousas | city | Louisiana | United States | 30.53 | -92.08 | 59 | |
| Open Acres | city | Alabama | United States | 32.44 | -86.28 | 200 | |
| Open Acres Manor | city | Maryland | United States | 39.49 | -76.37 | 298 | |
| Open Fork | city | Virginia | United States | 37.04 | -82.35 | 1699 | |
| Open Gate Trailer Park | city | Florida | United States | 27.14 | -80.22 | 13 | |
| Open Gates | city | Kentucky | United States | 38.01 | -84.54 | 1000 | |
| Open Sands | city | Florida | United States | 30.21 | -85.86 | 0 | |
| Openwood Plantation | city | Mississippi | United States | 32.40 | -90.80 | 298 | |
| Opequon | city | Virginia | United States | 39.16 | -78.25 | 898 | |
| Opequon Farms | city | Maryland | United States | 39.55 | -77.84 | 830 | |
| Opera (historical) | city | Ohio | United States | 39.91 | -82.16 | 997 | |
| Opera Plaza | city | California | United States | 37.78 | -122.42 | 160 | |
| Opheim | city | Montana | United States | 48.86 | -106.41 | 3349 | |
| Ophelia | city | Virginia | United States | 37.91 | -76.28 | 3 | |
| Ophelia (historical) | city | Mississippi | United States | 32.56 | -89.82 | 308 | |
| Ophelia (historical) | city | West Virginia | United States | 38.21 | -80.72 | 2700 | |
| Ophiem | city | Illinois | United States | 41.25 | -90.39 | 830 | |
| Ophir | city | Arkansas | United States | 34.44 | -93.61 | 830 | |
| Ophir | city | Alabama | United States | 34.36 | -85.95 | 1138 | |
| Ophir | city | Colorado | United States | 37.86 | -107.83 | 10068 | |
| Ophir | city | Georgia | United States | 34.33 | -84.26 | 1197 | |
| Ophir | city | Kentucky | United States | 37.91 | -83.01 | 1036 | |
| Ophir | city | North Carolina | United States | 35.48 | -79.98 | 830 | |
| Ophir | city | Oregon | United States | 42.56 | -124.38 | 196 | |
| Ophir | city | Alaska | United States | 63.14 | -156.52 | 830 | |
| Ophir | city | Utah | United States | 40.37 | -112.26 | 8389 | |
| Ophir | city | Washington | United States | 48.21 | -119.72 | 830 | |
| Ophir | city | California | United States | 38.89 | -121.12 | 830 | |
| Ophir (historical) | city | Nevada | United States | 38.95 | -117.27 | 7811 | |
| Ophir (historical) | city | Montana | United States | 47.93 | -110.47 | 2598 | |
| Ophir City (historical) | city | Nevada | United States | 39.29 | -119.83 | 5085 | |
| Ophir Hill Acres | city | California | United States | 39.19 | -121.04 | 3349 | |
| Ophir Loop | city | Colorado | United States | 37.86 | -107.87 | 10098 | |
| Opie | city | Virginia | United States | 36.77 | -78.18 | 400 | |
| Opihikao | city | Hawaii | United States | 19.43 | -154.88 | 0 | |
| Opine | city | Alabama | United States | 31.33 | -86.29 | 331 | |
| Opine | city | Alabama | United States | 31.90 | -87.93 | 173 | |
| Opitz (historical) | city | Arkansas | United States | 34.49 | -92.64 | 265 | |
| Oplin | city | Texas | United States | 32.14 | -99.56 | 1994 | |
| Opole | city | Minnesota | United States | 45.75 | -94.37 | 1135 | |
| Opolis | city | Kansas | United States | 37.34 | -94.62 | 915 | |
| Oponys Town (historical) | city | Florida | United States | 27.78 | -81.80 | 111 | |
| Opossum | city | Tennessee | United States | 35.71 | -89.56 | 396 | |
| Opossum (historical) | city | Tennessee | United States | 36.58 | -82.78 | 1669 | |
| Opossum Creek Pines | city | Tennessee | United States | 35.31 | -85.10 | 830 | |
| Opossum Point Landing | city | South Carolina | United States | 32.18 | -80.77 | 3 | |
| Opp | city | Alabama | United States | 31.28 | -86.26 | 334 | |
| Oppelo | city | Arkansas | United States | 35.10 | -92.77 | 298 | |
| Oppenheim | city | New York | United States | 43.07 | -74.69 | 1036 | |
| Oppenheimer | city | Pennsylvania | United States | 40.12 | -78.47 | 1669 | |
| Opperman | city | Ohio | United States | 39.89 | -81.60 | 997 | |
| Oppermans Corner | city | Pennsylvania | United States | 40.08 | -75.63 | 830 | |
| Opportunity | city | Montana | United States | 46.11 | -112.83 | 5029 | |
| Opportunity | city | Nebraska | United States | 42.60 | -98.50 | 1938 | |
| Opportunity | city | Washington | United States | 47.66 | -117.24 | 2076 | |
| Opportunity Farms | city | Missouri | United States | 38.23 | -93.46 | 856 | |
| Opposition (historical) | city | Arkansas | United States | 36.23 | -91.30 | 830 | |
| Ops | city | North Dakota | United States | 48.23 | -97.60 | 925 | |
| Opstead | city | Minnesota | United States | 46.23 | -93.47 | 1669 | |
| Optima | city | Oklahoma | United States | 36.76 | -101.36 | 3349 | |
| Optimo | city | New Mexico | United States | 35.89 | -104.80 | 6709 | |
| Optimus | city | Arkansas | United States | 36.04 | -92.13 | 830 | |
| Option | city | Pennsylvania | United States | 40.35 | -79.97 | 1102 | |
| Opun | city | Federated States of Micronesia | United States | 7.35 | 151.78 | 0 |