| 2009 | |
|---|---|
| Nairobi (City) | 985 016 |
| Kiambu | 482 450 |
| Nakuru | 409 836 |
| Meru | 381 026 |
| Kakamega | 355 679 |
| Bungoma | 270 824 |
| Kisii | 269 683 |
| Mombasa | 268 700 |
| Machakos | 264 500 |
| Muranga | 242 490 |
| Kisumu | 226 719 |
| Homa Bay | 206 255 |
| Kitui | 205 491 |
| Uasin Gishu | 202 291 |
| Nyeri | 201 703 |
| Kilifi | 199 764 |
| Siaya | 199 034 |
| Makueni | 186 478 |
| Migori | 180 211 |
| Bomet | 174 914 |
| Kajiado | 173 464 |
| Trans Nzoia | 170 117 |
| Narok | 169 220 |
| Busia | 154 225 |
| Kirinyaga | 154 220 |
| Nandi | 154 073 |
| Nyandarua | 143 879 |
| Embu | 131 683 |
| Kericho | 127 581 |
| Mandera | 125 497 |
| Vihiga | 123 347 |
| Turkana | 123 191 |
| Kwale | 122 047 |
| Baringo | 110 649 |
| Nyamira | 106 385 |
| Laikipia | 103 114 |
| Garissa | 98 590 |
| West Pokot | 93 777 |
| Wajir | 88 574 |
| Elgeyo Marakwet | 77 555 |
| Taita Taveta | 71 090 |
| Marsabit | 56 941 |
| Tana River | 47 414 |
| Samburu | 47 354 |
| Isiolo | 31 326 |
| Tharaka Nithi | 27 393 |
| Lamu | 22 184 |