| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
| Obadagahadeniya | city | Southern Province | Sri Lanka | 6.2575 | 80.6722222 | 469 | 47819 |
| Obadakotuwa | city | North Western Province | Sri Lanka | 7.6333333 | 80.3333333 | 351 | 45406 |
| Obadawatta | city | Southern Province | Sri Lanka | 6.4166667 | 80 | 3 | 68760 |
| Obadayagama | city | North Central Province | Sri Lanka | 8.1833333 | 80.5666667 | 403 | 15495 |
| Obbekota | city | Province of Uva | Sri Lanka | 6.9333333 | 81.35 | 587 | 9721 |
| Obberiya | city | Western Province | Sri Lanka | 7.2666667 | 79.8666667 | 19 | 68962 |
| Obedagedere | city | North Western Province | Sri Lanka | 7.3 | 80.15 | 242 | 92078 |
| Obodagedara | city | North Western Province | Sri Lanka | 7.3 | 80.15 | 242 | 92078 |
| Obodakotuwa | city | North Western Province | Sri Lanka | 7.6333333 | 80.3333333 | 351 | 45406 |
| Obodayagama | city | North Central Province | Sri Lanka | 7.95 | 80.4166667 | 475 | 32142 |
| Obokka | city | Province of Sabaragamuwa | Sri Lanka | 6.5166667 | 80.4 | 994 | 44628 |
| Odakkarai | city | North Western Province | Sri Lanka | 8.1333333 | 79.7 | 3 | 7372 |
| Oddaimavadi | city | North Eastern Province | Sri Lanka | 7.9166667 | 81.5166667 | 3 | 19148 |
| Oddamavadi | city | North Eastern Province | Sri Lanka | 7.9166667 | 81.5166667 | 3 | 19148 |
| Oddankulam | city | North Eastern Province | Sri Lanka | 9.1166667 | 80.2666667 | 75 | 5648 |
| Oddape | city | Province of Sabaragamuwa | Sri Lanka | 7.3333333 | 80.3666667 | 456 | 62206 |
| Oddare | city | Province of Sabaragamuwa | Sri Lanka | 7.3333333 | 80.3666667 | 456 | 62206 |
| Oddaruthakulam | city | North Eastern Province | Sri Lanka | 9.1333333 | 80.3333333 | 104 | 5381 |
| Oddaruttakulam | city | North Eastern Province | Sri Lanka | 9.1333333 | 80.3333333 | 104 | 5381 |
| Oddichuddan | city | North Eastern Province | Sri Lanka | 9.15 | 80.65 | 114 | 5676 |
| Oddiyadimady | city | North Eastern Province | Sri Lanka | 8.7833333 | 81.0833333 | 16 | 17243 |
| Odduchuddan | city | North Eastern Province | Sri Lanka | 9.15 | 80.65 | 114 | 5676 |
| Oddumadu | city | North Eastern Province | Sri Lanka | 8.1333333 | 81.4333333 | 9 | 13337 |
| Oddupeli | city | North Eastern Province | Sri Lanka | 9.65 | 80.25 | 3 | 59487 |
| Oddusudan | city | North Eastern Province | Sri Lanka | 9.15 | 80.65 | 114 | 5676 |
| Oddusuddan | city | North Eastern Province | Sri Lanka | 9.15 | 80.65 | 114 | 5676 |
| Oggamuwa | city | North Western Province | Sri Lanka | 7.2666667 | 80.1833333 | 282 | 92635 |
| Oggomuwa | city | North Western Province | Sri Lanka | 7.2666667 | 80.1833333 | 282 | 92635 |
| Oggomuwa | city | North Western Province | Sri Lanka | 7.55 | 80.3166667 | 433 | 45414 |
| Oggomuwa | city | Central Province | Sri Lanka | 7.5333333 | 80.9333333 | 393 | 34487 |
| Ogodapola | city | North Western Province | Sri Lanka | 7.6333333 | 80 | 98 | 45406 |
| Ogodapola | city | Western Province | Sri Lanka | 7.1 | 80.1 | 291 | 163471 |
| Ogodapola | city | North Western Province | Sri Lanka | 7.4333333 | 80.3333333 | 482 | 45755 |
| Ogodapola | city | Central Province | Sri Lanka | 7.3666667 | 80.5166667 | 951 | 73905 |
| Ohiya | city | Province of Uva | Sri Lanka | 6.8166667 | 80.8333333 | 6889 | 50118 |
| Ohomigama | city | North Central Province | Sri Lanka | 7.9166667 | 80.4833333 | 652 | 21839 |
| Okanda | city | North Eastern Province | Sri Lanka | 6.65 | 81.7666667 | 29 | 9594 |
| Okandapola | city | North Western Province | Sri Lanka | 7.3666667 | 80.3166667 | 505 | 52278 |
| Okandeyaya | city | Southern Province | Sri Lanka | 6.2166667 | 80.7833333 | 426 | 32333 |
| Okanduwa | city | Western Province | Sri Lanka | 6.7 | 80.0166667 | 180 | 88688 |
| Okanmulla | city | Province of Sabaragamuwa | Sri Lanka | 6.6833333 | 80.7 | 1981 | 44467 |
| Okanta | city | North Eastern Province | Sri Lanka | 6.65 | 81.7666667 | 29 | 9594 |
| Okawala | city | Southern Province | Sri Lanka | 6.1 | 80.7166667 | 439 | 39395 |
| Okewela | city | Southern Province | Sri Lanka | 6.1 | 80.7166667 | 439 | 39395 |
| Okewelagoda | city | Southern Province | Sri Lanka | 6.1 | 80.7166667 | 439 | 39395 |
| Okkampitiya | city | Province of Uva | Sri Lanka | 6.75 | 81.2833333 | 419 | 9721 |
| Okkampitiya Ihalagama | city | Province of Uva | Sri Lanka | 6.75 | 81.2833333 | 419 | 9721 |
| Okurawa | city | Province of Uva | Sri Lanka | 6.75 | 81.1833333 | 574 | 9721 |
| Okuruwawa | city | Province of Uva | Sri Lanka | 6.75 | 81.1833333 | 574 | 9721 |
| Olabaduwa | city | Western Province | Sri Lanka | 6.7666667 | 80.0166667 | 269 | 219608 |
| Olaboduwa | city | Western Province | Sri Lanka | 6.7666667 | 80.0166667 | 269 | 219608 |
| Olagama | city | Southern Province | Sri Lanka | 6.25 | 80.05 | 22 | 54674 |
| Olagama | city | Southern Province | Sri Lanka | 6.15 | 80.1 | 13 | 51574 |
| Olagama | city | Province of Sabaragamuwa | Sri Lanka | 7.25 | 80.35 | 987 | 64716 |
| Olagama | city | North Western Province | Sri Lanka | 7.5166667 | 80.5 | 908 | 43069 |
| Olaganduwa | city | Southern Province | Sri Lanka | 6.3833333 | 80.0166667 | 6 | 59355 |
| Olaganwatta | city | Central Province | Sri Lanka | 7.65 | 80.6 | 1351 | 30963 |
| Olaithoduvai | city | North Eastern Province | Sri Lanka | 9.0333333 | 79.8333333 | 19 | 4202 |
| Olaittoduvai | city | North Eastern Province | Sri Lanka | 9.0333333 | 79.8333333 | 19 | 4202 |
| Olaittoduvl | city | North Eastern Province | Sri Lanka | 9.0333333 | 79.8333333 | 19 | 4202 |
| Old Peradeniya | city | Central Province | Sri Lanka | 7.2630556 | 80.6027778 | 1630 | 75752 |
| Olidivullewa | city | North Western Province | Sri Lanka | 7.95 | 80.3333333 | 331 | 45372 |
| Oligama | city | North Western Province | Sri Lanka | 7.6 | 80.1 | 383 | 45410 |
| Oligama | city | Central Province | Sri Lanka | 7.7166667 | 80.5833333 | 1007 | 32640 |
| Oligoda | city | Southern Province | Sri Lanka | 6.3666667 | 80.0166667 | 6 | 48682 |
| Olimadu | city | North Eastern Province | Sri Lanka | 9.15 | 80.4833333 | 127 | 5823 |
| Olimadu | city | North Eastern Province | Sri Lanka | 7.6666667 | 81.5666667 | 154 | 24841 |
| Olindakadawela | city | North Western Province | Sri Lanka | 7.8 | 80.3833333 | 488 | 45386 |
| Olindankadawala | city | North Western Province | Sri Lanka | 7.8 | 80.3833333 | 488 | 45386 |
| Olitenna | city | Province of Sabaragamuwa | Sri Lanka | 6.7 | 80.7833333 | 1755 | 43735 |
| Oliyamulla | city | North Western Province | Sri Lanka | 7.4333333 | 80.4333333 | 646 | 47245 |
| Oliyanyaya | city | North Eastern Province | Sri Lanka | 7.2166667 | 81.65 | 429 | 16637 |
| Ollimadu | city | North Eastern Province | Sri Lanka | 8.85 | 79.9666667 | 13 | 9574 |
| Olobbawa | city | North Central Province | Sri Lanka | 8.0166667 | 80.5833333 | 429 | 15502 |
| Olombewa | city | North Central Province | Sri Lanka | 8.0166667 | 80.5833333 | 429 | 15502 |
| Oluara | city | Southern Province | Sri Lanka | 6.1666667 | 80.6833333 | 475 | 37294 |
| Olugala | city | Province of Sabaragamuwa | Sri Lanka | 6.7166667 | 80.4333333 | 610 | 44071 |
| Olugallewa | city | North Central Province | Sri Lanka | 8.35 | 80.75 | 351 | 15488 |
| Olugantota | city | Province of Sabaragamuwa | Sri Lanka | 6.65 | 80.7166667 | 1971 | 44031 |
| Olugaskada | city | North Central Province | Sri Lanka | 8.6666667 | 80.6333333 | 383 | 15357 |
| Olugaskada | city | North Central Province | Sri Lanka | 8.7333333 | 80.7666667 | 209 | 15474 |
| Olugaskada | city | North Central Province | Sri Lanka | 8.5333333 | 80.8166667 | 239 | 15484 |
| Olugaskadawala | city | North Central Province | Sri Lanka | 8.6 | 80.8333333 | 239 | 15478 |
| Olugaskadawela | city | North Central Province | Sri Lanka | 8.6 | 80.8333333 | 239 | 15478 |
| Olugollewa | city | North Central Province | Sri Lanka | 8.35 | 80.75 | 351 | 15488 |
| Olukaranda | city | North Central Province | Sri Lanka | 8.0666667 | 80.6 | 505 | 15499 |
| Olukkiliya | city | North Western Province | Sri Lanka | 8.05 | 79.95 | 121 | 30003 |
| Olukkulam | city | North Eastern Province | Sri Lanka | 9.1 | 80.1 | 3 | 7526 |
| Olukkulam | city | North Eastern Province | Sri Lanka | 8.6666667 | 80.4 | 239 | 9810 |
| Olumadu | city | North Eastern Province | Sri Lanka | 8.6666667 | 80.3166667 | 177 | 8772 |
| Olumadu | city | North Eastern Province | Sri Lanka | 9.15 | 80.4833333 | 127 | 5823 |
| Olumadu | city | North Eastern Province | Sri Lanka | 9.0166667 | 80.6666667 | 180 | 8133 |
| Olupanduruwewa | city | North Central Province | Sri Lanka | 8.4166667 | 80.2333333 | 223 | 15484 |
| Olupeliya | city | Southern Province | Sri Lanka | 6.0833333 | 80.6833333 | 492 | 61958 |
| Olupeliyawa | city | North Western Province | Sri Lanka | 7.6166667 | 79.9833333 | 72 | 45150 |
| Olupeliyawa | city | North Western Province | Sri Lanka | 7.8 | 80.1 | 219 | 45386 |
| Olupeliyawa | city | North Western Province | Sri Lanka | 7.45 | 80.35 | 498 | 46257 |
| Oluvil | city | North Eastern Province | Sri Lanka | 7.2833333 | 81.85 | 13 | 10789 |
| Oluwawatta | city | Central Province | Sri Lanka | 7.2 | 80.7333333 | 2627 | 73130 |
| Oluwewa | city | North Central Province | Sri Lanka | 8.25 | 80.2166667 | 262 | 15495 |
| Omalpe | city | Province of Sabaragamuwa | Sri Lanka | 6.3333333 | 80.6833333 | 2001 | 52528 |
| Omantai | city | North Eastern Province | Sri Lanka | 8.8666667 | 80.5 | 285 | 8769 |
| Omaragolla | city | North Western Province | Sri Lanka | 7.7 | 80.5333333 | 1023 | 39959 |
| Omatta | city | Southern Province | Sri Lanka | 6.35 | 80.1666667 | 337 | 90702 |
| Omatta | city | Western Province | Sri Lanka | 6.5666667 | 80.1833333 | 498 | 88694 |
| Omuna | city | North Eastern Province | Sri Lanka | 7.6166667 | 81.2666667 | 465 | 16571 |
| Onagama | city | North Central Province | Sri Lanka | 7.9833333 | 81.0833333 | 85 | 14294 |
| Ondachchimadam | city | North Eastern Province | Sri Lanka | 7.5 | 81.8 | 3 | 11946 |
| Onegama | city | North Central Province | Sri Lanka | 7.9833333 | 81.0833333 | 85 | 14294 |
| Opalagala | city | Central Province | Sri Lanka | 7.6175 | 80.6894444 | 1925 | 30314 |
| Opalgala | city | Central Province | Sri Lanka | 7.6175 | 80.6894444 | 1925 | 30314 |
| Opalgalawatta | city | Central Province | Sri Lanka | 7.55 | 80.6666667 | 1637 | 30318 |
| Opalla | city | Western Province | Sri Lanka | 6.7 | 80.1333333 | 446 | 86967 |
| Opalla | city | Central Province | Sri Lanka | 7.3833333 | 80.5 | 971 | 67441 |
| Opanake | city | Province of Sabaragamuwa | Sri Lanka | 6.6127778 | 80.6194444 | 787 | 44034 |
| Opata | city | Western Province | Sri Lanka | 7.1333333 | 79.9166667 | 19 | 169545 |
| Opata | city | Southern Province | Sri Lanka | 6.3666667 | 80.15 | 236 | 90835 |
| Opata | city | Southern Province | Sri Lanka | 6.1 | 80.2 | 164 | 82180 |
| Opata | city | Province of Sabaragamuwa | Sri Lanka | 7.2833333 | 80.2333333 | 341 | 64752 |
| Opata | city | Southern Province | Sri Lanka | 6.2666667 | 80.4 | 495 | 91549 |
| Opata | city | Province of Sabaragamuwa | Sri Lanka | 6.5666667 | 80.6 | 967 | 44038 |
| Opata | city | Province of Sabaragamuwa | Sri Lanka | 6.5333333 | 80.6666667 | 1003 | 44041 |
| Opatha | city | Western Province | Sri Lanka | 7.1333333 | 79.9166667 | 19 | 169545 |
| Opatha | city | Province of Sabaragamuwa | Sri Lanka | 7.2833333 | 80.2333333 | 341 | 64752 |
| Opathella | city | Western Province | Sri Lanka | 7.0833333 | 80.0833333 | 295 | 169576 |
| Orukmankulama | city | North Central Province | Sri Lanka | 8.25 | 80.5333333 | 351 | 15492 |
| Oruliyadda | city | North Western Province | Sri Lanka | 7.3166667 | 80.3 | 393 | 58083 |
| Orulotagama | city | North Central Province | Sri Lanka | 8 | 80.6 | 452 | 15697 |
| Orumulacholai | city | North Eastern Province | Sri Lanka | 7.8 | 81.5833333 | 52 | 22033 |
| Orutota | city | Western Province | Sri Lanka | 7.0833333 | 79.9833333 | 42 | 169576 |
| Orutotagama | city | North Central Province | Sri Lanka | 8 | 80.6 | 452 | 15697 |
| Oruwala | city | Western Province | Sri Lanka | 6.8833333 | 80 | 265 | 388255 |
| Oruwela | city | Western Province | Sri Lanka | 6.8833333 | 80 | 265 | 388255 |
| Otagama | city | Central Province | Sri Lanka | 7.2833333 | 80.8833333 | 2109 | 75752 |
| Otalawa | city | Central Province | Sri Lanka | 7.0666667 | 80.6666667 | 2696 | 65626 |
| Otara Bemmullegedara | city | North Western Province | Sri Lanka | 7.3833333 | 80.2166667 | 383 | 45431 |
| Otara Tambarawila | city | North Western Province | Sri Lanka | 7.2833333 | 79.8833333 | 16 | 104077 |
| Otarakiriwanapola | city | North Western Province | Sri Lanka | 7.3 | 80.1833333 | 406 | 69151 |
| Otaravadiya | city | North Western Province | Sri Lanka | 7.2833333 | 79.9333333 | 36 | 122005 |
| Otarawadiya | city | North Western Province | Sri Lanka | 7.2833333 | 79.9333333 | 36 | 122005 |
| Otegama | city | North Western Province | Sri Lanka | 7.6166667 | 80.1 | 200 | 45410 |
| Othegama | city | North Western Province | Sri Lanka | 7.5 | 79.9333333 | 59 | 41510 |
| Otherabemmullegedera | city | North Western Province | Sri Lanka | 7.3833333 | 80.2166667 | 383 | 45431 |
| Otherakiriwanapola | city | North Western Province | Sri Lanka | 7.3 | 80.1833333 | 406 | 69151 |
| Othiyamalai | city | North Eastern Province | Sri Lanka | 9.05 | 80.7 | 131 | 7060 |
| Othiyankuda-aru | city | North Eastern Province | Sri Lanka | 7.6 | 81.6166667 | 334 | 24847 |
| Otiyamalai | city | North Eastern Province | Sri Lanka | 9.05 | 80.7 | 131 | 7060 |
| Otnapitiya | city | Province of Sabaragamuwa | Sri Lanka | 7.2166667 | 80.25 | 498 | 64418 |
| Ottapanai | city | North Western Province | Sri Lanka | 7.8208333 | 79.7883333 | 6 | 12311 |
| Ottapanai Periya | city | North Western Province | Sri Lanka | 7.8208333 | 79.7883333 | 6 | 12311 |
| Ottapanai Sinna | city | North Western Province | Sri Lanka | 7.8166667 | 79.7833333 | 16 | 12311 |
| Ottappuwa | city | North Central Province | Sri Lanka | 8.1833333 | 80.25 | 229 | 16877 |
| Ottappuwe | city | North Central Province | Sri Lanka | 8.1833333 | 80.25 | 229 | 16877 |
| Ottapuwe Galatabendiwewa | city | North Central Province | Sri Lanka | 8.1833333 | 80.25 | 229 | 16877 |
| Ottukulama | city | North Western Province | Sri Lanka | 7.9333333 | 80.1166667 | 229 | 36908 |
| Ottukulama | city | North Western Province | Sri Lanka | 8.0166667 | 80.25 | 305 | 45359 |
| Ottukulama | city | North Western Province | Sri Lanka | 8.0666667 | 80.2666667 | 318 | 43645 |
| Ottukulama | city | North Western Province | Sri Lanka | 8.0333333 | 80.3 | 301 | 44491 |
| Ottupillama | city | North Western Province | Sri Lanka | 7.6 | 79.95 | 68 | 41239 |
| Oture | city | Southern Province | Sri Lanka | 6.0833333 | 80.6833333 | 492 | 61958 |
| Otuwela | city | North Western Province | Sri Lanka | 7.6333333 | 80.3833333 | 495 | 45406 |
| Ovilikanda | city | Southern Province | Sri Lanka | 7.45 | 80.5666667 | 2270 | 54385 |
| Ovilla | city | Southern Province | Sri Lanka | 7.45 | 80.5833333 | 2086 | 54385 |
| Ovisa | city | Central Province | Sri Lanka | 7.3833333 | 80.6 | 1945 | 60449 |
| Ovitipana | city | Southern Province | Sri Lanka | 7.5333333 | 80.6 | 2998 | 32283 |
| Owala | city | Province of Sabaragamuwa | Sri Lanka | 6.7 | 80.4833333 | 521 | 44027 |
| Owala | city | Central Province | Sri Lanka | 7.2666667 | 80.5666667 | 1948 | 75528 |
| Owala | city | Central Province | Sri Lanka | 7.5166667 | 80.65 | 1374 | 30321 |
| Owala Kudabage | city | Province of Sabaragamuwa | Sri Lanka | 6.7 | 80.4833333 | 521 | 44027 |
| Owala Mahabage | city | Province of Sabaragamuwa | Sri Lanka | 6.7 | 80.4833333 | 521 | 44027 |
| Owalapolwatta | city | Central Province | Sri Lanka | 7.5333333 | 80.6333333 | 1361 | 30321 |
| Owatta | city | Province of Sabaragamuwa | Sri Lanka | 7.3 | 80.3833333 | 469 | 64812 |
| Owatta | city | Province of Sabaragamuwa | Sri Lanka | 7.25 | 80.4666667 | 944 | 67926 |
| Owattewela | city | North Western Province | Sri Lanka | 7.4333333 | 80.4666667 | 551 | 51300 |
| Owatura | city | Province of Sabaragamuwa | Sri Lanka | 6.5833333 | 80.7833333 | 610 | 44038 |
| Owilana | city | Southern Province | Sri Lanka | 6.0166667 | 80.7333333 | 118 | 37827 |
| Owilikanda | city | Southern Province | Sri Lanka | 7.45 | 80.5666667 | 2270 | 54385 |
| Owilla | city | Southern Province | Sri Lanka | 7.45 | 80.5833333 | 2086 | 54385 |
| Owisa | city | Central Province | Sri Lanka | 7.3833333 | 80.6 | 1945 | 60449 |
| Owitigala | city | Western Province | Sri Lanka | 6.5 | 80.1166667 | 436 | 88730 |
| Owitigama | city | Western Province | Sri Lanka | 6.8333333 | 80.0333333 | 416 | 349302 |
| Owitigama | city | Western Province | Sri Lanka | 6.9666667 | 80.1166667 | 49 | 229608 |
| Owitigamuwa | city | Province of Sabaragamuwa | Sri Lanka | 7.1333333 | 80.3833333 | 980 | 64824 |
| Owitigamuwa | city | Southern Province | Sri Lanka | 6.0666667 | 80.6 | 337 | 89711 |
| Owitipana | city | Southern Province | Sri Lanka | 7.5333333 | 80.6 | 2998 | 32283 |
| Owitiwara | city | Province of Sabaragamuwa | Sri Lanka | 7.3 | 80.3666667 | 469 | 62206 |
| Owitiyagala | city | Western Province | Sri Lanka | 6.7333333 | 80.05 | 301 | 94503 |
| Oyatenna | city | Central Province | Sri Lanka | 7.35 | 80.9166667 | 1112 | 72461 |
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