| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| O. Cordero Palacios | city | Azuay | Ecuador | -2.80 | -78.97 | 9228 | 34048 |
| OCC (FRANCISCO DE ORELLANA) | airport | Ecuador | -0.46 | -76.99 | 834 | 0 | |
| Oasis | city | Sucumbios | Ecuador | -0.46 | -76.11 | 830 | 60 |
| Obispopamba | city | El Oro | Ecuador | -3.48 | -79.62 | 10373 | 2345 |
| Obraje | city | Tungurahua | Ecuador | -1.31 | -78.53 | 7125 | 36268 |
| Ocampo | city | Imbabura | Ecuador | 0.31 | -78.27 | 7837 | 36971 |
| Octavio Cordero | city | Azuay | Ecuador | -2.80 | -78.97 | 9228 | 34048 |
| Octavio Cordero Palacios | city | Azuay | Ecuador | -2.80 | -78.97 | 9228 | 34048 |
| Olalla | city | Pichincha | Ecuador | -0.23 | -78.35 | 8763 | 25941 |
| Olan | city | Manabi | Ecuador | -1.82 | -80.75 | 177 | 3787 |
| Olguin | city | Cotopaxi | Ecuador | -1.05 | -78.62 | 8713 | 21675 |
| Oliva | city | Pichincha | Ecuador | -0.25 | -79.18 | 1820 | 72712 |
| Olive | city | Guayas | Ecuador | -2.12 | -79.85 | 9 | 87354 |
| Olivo | city | Esmeraldas | Ecuador | 0.98 | -79.42 | 196 | 5189 |
| Olmedo | city | Loja | Ecuador | -3.93 | -79.65 | 5029 | 8864 |
| Olmedo | city | Guayas | Ecuador | -2.39 | -80.44 | 830 | 2569 |
| Olmedo | city | Manabi | Ecuador | -1.40 | -80.21 | 377 | 6302 |
| Olmedo | city | Tungurahua | Ecuador | -1.34 | -78.55 | 8471 | 35765 |
| Olmedo | city | Pichincha | Ecuador | 0.15 | -78.07 | 10908 | 2309 |
| Olmedo | city | Esmeraldas | Ecuador | 1.22 | -79.05 | 0 | 5380 |
| Olmedo Perdomo | city | Esmeraldas | Ecuador | 0.72 | -80.09 | 830 | 1863 |
| Olon | city | Guayas | Ecuador | -1.77 | -80.77 | 203 | 3181 |
| Onashapa | city | Azuay | Ecuador | -3.45 | -79.12 | 8572 | 2308 |
| Once de Noviembre | city | Cotopaxi | Ecuador | -0.91 | -78.67 | 9265 | 34660 |
| Oncebi | city | Los Rios | Ecuador | -1.40 | -79.32 | 2509 | 7052 |
| Oncevi | city | Los Rios | Ecuador | -1.40 | -79.32 | 2509 | 7052 |
| Ontaneda | city | Pichincha | Ecuador | -0.30 | -78.50 | 8572 | 311110 |
| Ontanon | city | Imbabura | Ecuador | 0.33 | -78.22 | 8389 | 42999 |
| Opaluca | city | Loja | Ecuador | -4.02 | -79.67 | 4189 | 6677 |
| Opar | city | Canar | Ecuador | -2.73 | -78.83 | 9461 | 51466 |
| Opoluca | city | Loja | Ecuador | -4.02 | -79.67 | 4189 | 6677 |
| Opote | city | Chimborazo | Ecuador | -1.76 | -78.76 | 10908 | 12517 |
| Ordonez | city | Azuay | Ecuador | -2.82 | -78.77 | 9228 | 24733 |
| Ordonez Laso | city | Azuay | Ecuador | -2.82 | -78.77 | 9228 | 24733 |
| Ordonez Lazo | city | Azuay | Ecuador | -2.82 | -78.77 | 9228 | 24733 |
| Ordoñes | city | Pichincha | Ecuador | -0.35 | -78.43 | 8733 | 71715 |
| Oretga | city | Zamora-Chinchipe | Ecuador | -3.55 | -78.93 | 5029 | 536 |
| Organos | city | Loja | Ecuador | -4.12 | -80.17 | 1952 | 3353 |
| Orianga | city | Loja | Ecuador | -3.90 | -79.87 | 5029 | 1974 |
| Ornopata | city | Canar | Ecuador | -2.80 | -78.92 | 8389 | 28703 |
| Orta | city | Loja | Ecuador | -4.22 | -79.23 | 5869 | 3921 |
| Ortega | city | Tungurahua | Ecuador | -1.23 | -78.56 | 8389 | 117658 |
| Ortega | city | Pichincha | Ecuador | -0.30 | -78.55 | 10068 | 488738 |
| Ortega | city | Azuay | Ecuador | -2.83 | -78.82 | 9228 | 23383 |
| Ortega Alto | city | Zamora-Chinchipe | Ecuador | -3.52 | -78.92 | 6102 | 306 |
| Ortega Bajo | city | Zamora-Chinchipe | Ecuador | -3.53 | -78.91 | 5892 | 433 |
| Ortuno | city | Cotopaxi | Ecuador | -0.72 | -78.63 | 10173 | 11789 |
| Osayacu | city | Napo | Ecuador | -0.77 | -77.78 | 3431 | 447 |
| Oso | city | Imbabura | Ecuador | 0.70 | -78.30 | 5869 | 1383 |
| Osorio | city | Pichincha | Ecuador | -0.15 | -78.50 | 9274 | 538474 |
| Ostiones | city | Esmeraldas | Ecuador | 1.05 | -79.31 | 45 | 1802 |
| Otavalas | city | Imbabura | Ecuador | 0.23 | -78.26 | 8530 | 44895 |
| Otavalo | city | Imbabura | Ecuador | 0.23 | -78.26 | 8530 | 44895 |
| Otilia | city | Guayas | Ecuador | -1.92 | -79.53 | 144 | 15315 |
| Oton | city | Pichincha | Ecuador | -0.01 | -78.27 | 8402 | 13238 |
| Oton | city | Pichincha | Ecuador | -0.02 | -78.26 | 9494 | 13134 |
| Oton Llano | city | Pichincha | Ecuador | -0.03 | -78.27 | 10068 | 13982 |
| Otoncito | city | Pichincha | Ecuador | -0.02 | -78.23 | 10068 | 12482 |
| Otongo | city | Santo Domingo de los Tsachilas | Ecuador | -0.39 | -79.19 | 2808 | 3456 |
| Otongo de Baba | city | Santo Domingo de los Tsachilas | Ecuador | -0.36 | -79.20 | 2509 | 14990 |
| Otono | city | Guayas | Ecuador | -1.91 | -79.63 | 101 | 12645 |
| Otovalo | city | Imbabura | Ecuador | 0.23 | -78.26 | 8530 | 44895 |
| Ovalo | city | Pichincha | Ecuador | -0.37 | -78.40 | 9228 | 39825 |
| Ovejería | city | Pichincha | Ecuador | -0.62 | -78.45 | 12906 | 2674 |
| Ovejería | city | Carchi | Ecuador | 0.80 | -77.78 | 10068 | 34258 |
| Ovejo | city | Carchi | Ecuador | 0.83 | -77.98 | 12588 | 2818 |
| Oyacachi | city | Napo | Ecuador | -0.21 | -78.07 | 11095 | 483 |
| Oyacoto | city | Pichincha | Ecuador | -0.10 | -78.39 | 6912 | 62452 |
| Oyambaro | city | Pichincha | Ecuador | -0.21 | -78.33 | 10068 | 23784 |
| Oña | city | Azuay | Ecuador | -3.47 | -79.15 | 8592 | 2167 |