| Area Km2 | Population as per 2001 census | |
| Western Province | ||
| Colombo District | ||
| Colombo | 18 | 380,946 |
| Kolonnawa | 28 | 161,247 |
| Kaduwela | 88 | 209,251 |
| Homagama | 121 | 186,050 |
| Hanwella | 150 | 94,001 |
| Maharagama | 38 | 185,193 |
| Sri Jayawardanapura Kotte | 17 | 116,366 |
| Moratuwa | 20 | 177,563 |
| Kesbewa | 64 | 209,619 |
| Ratmalana | 13 | 106,716 |
| Thimbirigasyaya | 24 | 266,154 |
| Padukka | 110 | 54,338 |
| Dehiwala - Mount Laviniya | 8 | 101.83 |