| Town Name | Type | Region | Province / State | County | Municipality | Population | Latitude | Longitude | |
|---|---|---|---|---|---|---|---|---|---|
| Ogíjares | town | 13403 | 37.118813 | -3.609129 | Map | ||||
| Ojén | village | 2949 | 36.563850 | -4.855721 | Map | ||||
| Olakueta | village | Euskadi | Bizkaia | 4066 | 43.169666 | -2.575329 | Map | ||
| Olesa de Montserrat | town | 23646 | 41.543053 | 1.893187 | Map | ||||
| Oliana | village | 1843 | 42.067162 | 1.314942 | Map | ||||
| Olías del Rey | village | Castilla-La Mancha | Toledo | 7175 | 39.944736 | -3.987252 | Map | ||
| Olite | village | 3722 | 42.481083 | -1.651575 | Map | ||||
| Oliva | town | 23726 | 38.920200 | -0.120974 | Map | ||||
| Oliva de la Frontera | village | Extremadura | Badajoz | 5573 | 38.276699 | -6.918071 | Map | ||
| Oliva de Mérida | village | 1844 | 38.789951 | -6.124346 | Map | ||||
| Olivares | village | 1038 | 37.331921 | -3.765099 | Map | ||||
| Olivares | village | 9534 | 37.416710 | -6.156429 | Map | ||||
| Olivenza | town | Extremadura | Badajoz | 12008 | 38.684475 | -7.100566 | Map | ||
| Olmedo | village | 3885 | 41.287098 | -4.686690 | Map | ||||
| Olocau | town | 1482 | 39.700676 | -0.531206 | Map | ||||
| Olost | village | 1037 | 41.985294 | 2.094162 | Map | ||||
| Olot | town | 24070 | 42.182194 | 2.489016 | Map | ||||
| Olula del Río | village | 6152 | 37.355270 | -2.296593 | Map | ||||
| Ólvega | village | 3641 | 41.779564 | -1.984363 | Map | ||||
| Olvera | village | 8570 | 36.934650 | -5.259907 | Map | ||||
| Oñati | town | Euskal Herria / País | Gipuzkoa | 11151 | 43.032852 | -2.413715 | Map | ||
| Onda | town | 23592 | 39.962151 | -0.259385 | Map | ||||
| Ondara | village | 6570 | 38.827728 | 0.016940 | Map | ||||
| Ondarroa | town | Euskadi | Bizkaia | 8856 | 43.320728 | -2.420750 | Map | ||
| Onil | village | 7723 | 38.629574 | -0.673842 | Map |