| Town Name | Type | Region | Province / State | County | Municipality | Population | Latitude | Longitude | |
|---|---|---|---|---|---|---|---|---|---|
| Ontígola | village | 3874 | 40.003479 | -3.572782 | Map | ||||
| Ontinyent | town | 37935 | 38.821392 | -0.609622 | Map | ||||
| Ontur | village | 2318 | 38.615059 | -1.497719 | Map | ||||
| Orba | village | 2629 | 38.780376 | -0.063880 | Map | ||||
| Orce | village | 1243 | 37.721306 | -2.478503 | Map | ||||
| Orcera | village | 1948 | 38.317780 | -2.661190 | Map | ||||
| Ordes | town | 5823 | 43.076717 | -8.407819 | Map | ||||
| Ordizia | village | Euskadi | Gipuzkoa | 8938 | 43.053970 | -2.179505 | Map | ||
| Orellana la Vieja | village | Extremadura | Badajoz | 3010 | 39.004799 | -5.535224 | Map | ||
| Orgaz | village | 2758 | 39.647530 | -3.874867 | Map | ||||
| Órgiva | village | 4194 | 36.897221 | -3.422404 | Map | ||||
| Orihuela | town | 33470 | 38.090691 | -0.946613 | Map | ||||
| Orio | village | Euskal Herria / País | Gipuzkoa | 5382 | 43.276051 | -2.127262 | Map | ||
| Orkoien | town | 3511 | 42.823490 | -1.702268 | Map | ||||
| Ormaiztegi | village | Euskadi | Gipuzkoa | 1170 | 43.043125 | -2.254814 | Map | ||
| Orpesa/Oropesa del Mar | town | 5162 | 40.093208 | 0.135352 | Map | ||||
| Ortigueira | town | 1692 | 43.684315 | -7.854368 | Map | ||||
| Orusco de Tajuña | village | Comunidad de Madrid | Madrid | 1145 | 40.285339 | -3.209652 | Map | ||
| Osorno la Mayor | village | 1256 | 42.410671 | -4.360982 | Map | ||||
| Ossa de Montiel | village | 2593 | 38.962414 | -2.745302 | Map | ||||
| Osuna | town | 17683 | 37.237663 | -5.105840 | Map | ||||
| Otívar | village | 1136 | 36.815372 | -3.680964 | Map | ||||
| Otxandio | village | Euskal Herria / País | Bizkaia / Vizcaya | 1221 | 43.040791 | -2.654575 | Map | ||
| Ourense | city | 107186 | 42.343639 | -7.867424 | Map | ||||
| Oviedo / Uviéu | city | Principado de Asturi | Asturias | 216607 | 43.360634 | -5.844897 | Map |