| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
|---|
| Odiyattur | city | State of Tamil Nadu | India | 12.0333333 | 79.3666667 | 295 | 96585 |
| Odiyāttūr | city | State of Tamil Nadu | India | 12.0333333 | 79.3666667 | 295 | 96585 |
| Odugathur | city | State of Tamil Nadu | India | 12.7666667 | 78.9 | 1217 | 78316 |
| Odugattur | city | State of Tamil Nadu | India | 12.7666667 | 78.9 | 1217 | 78316 |
| Odugattūr | city | State of Tamil Nadu | India | 12.7666667 | 78.9 | 1217 | 78316 |
| Olakkur | city | State of Tamil Nadu | India | 12.3166667 | 79.7166667 | 157 | 73626 |
| Olakkūr | city | State of Tamil Nadu | India | 12.3166667 | 79.7166667 | 157 | 73626 |
| Olakur | city | State of Tamil Nadu | India | 12.3166667 | 79.7166667 | 157 | 73626 |
| Omalur | city | State of Tamil Nadu | India | 11.7333333 | 78.0666667 | 977 | 93129 |
| Omalūr | city | State of Tamil Nadu | India | 11.7333333 | 78.0666667 | 977 | 93129 |
| Ongur | city | State of Tamil Nadu | India | 12.3166667 | 79.7833333 | 134 | 73170 |
| Ongūr | city | State of Tamil Nadu | India | 12.3166667 | 79.7833333 | 134 | 73170 |
| Onnapuram | city | State of Tamil Nadu | India | 12.7166667 | 79.2 | 603 | 82693 |
| Onnupuram | city | State of Tamil Nadu | India | 12.7166667 | 79.2 | 603 | 82693 |
| Oorgaum | city | State of Tamil Nadu | India | 12.3 | 77.6166667 | 2027 | 23104 |
| Oossoor | city | State of Tamil Nadu | India | 12.7166667 | 77.8166667 | 2883 | 42811 |
| Ootacamund | city | State of Tamil Nadu | India | 11.4 | 76.7 | 7263 | 43297 |
| Ooty | city | State of Tamil Nadu | India | 11.4 | 76.7 | 7263 | 43297 |
| Opattur | city | State of Tamil Nadu | India | 12.85 | 80.0163889 | 111 | 82666 |
| Oragadam | city | State of Tamil Nadu | India | 12.8438889 | 79.9480556 | 154 | 87271 |
| Oragadam | city | State of Tamil Nadu | India | 12.65 | 80.0666667 | 131 | 101161 |
| Orattanad | city | State of Tamil Nadu | India | 10.6166667 | 79.2666667 | 6 | 78486 |
| Orattanadu | city | State of Tamil Nadu | India | 10.6166667 | 79.2666667 | 6 | 78486 |
| Orattanādu | city | State of Tamil Nadu | India | 10.6166667 | 79.2666667 | 6 | 78486 |
| Otacamund | city | State of Tamil Nadu | India | 11.4 | 76.7 | 7263 | 43297 |
| Otapidaram | city | State of Tamil Nadu | India | 8.9166667 | 78.0166667 | 147 | 37266 |
| Ottappidaram | city | State of Tamil Nadu | India | 8.9166667 | 78.0166667 | 147 | 37266 |
| Ottappidāram | city | State of Tamil Nadu | India | 8.9166667 | 78.0166667 | 147 | 37266 |
| Otteri | city | State of Tamil Nadu | India | 13.0880556 | 80.2525 | 55 | 2970775 |
| Ottiyanbakkam | city | State of Tamil Nadu | India | 12.8636111 | 80.1919444 | 32 | 96434 |
| Ovari Paravarnattam | city | State of Tamil Nadu | India | 8.2666667 | 77.9 | 0 | 17637 |
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