| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Oei Tiong Ham Park | city | Singapore | 1.32 | 103.79 | 3 | 928853 | |
| Old Kallang Airport Estate | city | Singapore | 1.31 | 103.90 | 3 | 1038574 | |
| Ong Lee | city | Singapore | 1.35 | 103.75 | 3 | 707035 | |
| Ong Lee Village | city | Singapore | 1.35 | 103.75 | 3 | 707035 | |
| Ong Ting Lye Estate | city | Singapore | 1.41 | 103.98 | 3 | 264283 | |
| Opera Estate | city | Singapore | 1.32 | 103.94 | 3 | 1015826 | |
| Outram Park | city | Singapore | 1.28 | 103.84 | 3 | 750625 |