| 2009 | |
|---|---|
| Nairobi (City) | 1 533 139 |
| Kakamega | 859 662 |
| Kiambu | 820 673 |
| Nakuru | 798 743 |
| Bungoma | 703 515 |
| Meru | 685 645 |
| Kisii | 601 818 |
| Kilifi | 574 209 |
| Machakos | 555 445 |
| Kitui | 531 427 |
| Homa Bay | 501 340 |
| Kisumu | 494 149 |
| Muranga | 484 717 |
| Migori | 472 814 |
| Mandera | 465 813 |
| Makueni | 453 817 |
| Mombasa | 452 446 |
| Uasin Gishu | 445 185 |
| Siaya | 443 652 |
| Narok | 421 894 |
| Trans Nzoia | 411 585 |
| Turkana | 410 330 |
| Busia | 387 824 |
| Nandi | 376 477 |
| Kericho | 376 359 |
| Bomet | 364 459 |
| Nyeri | 353 833 |
| Kajiado | 342 166 |
| Kwale | 333 934 |
| Nyamira | 311 204 |
| Nyandarua | 304 113 |
| Wajir | 298 175 |
| Vihiga | 291 906 |
| Garissa | 288 121 |
| Baringo | 276 480 |
| Kirinyaga | 267 424 |
| Embu | 261 909 |
| West Pokot | 257 863 |
| Laikipia | 200 602 |
| Tharaka Nithi | 186 879 |
| Elgeyo Marakwet | 186 260 |
| Marsabit | 140 054 |
| Taita Taveta | 139 323 |
| Tana River | 120 222 |
| Samburu | 111 940 |
| Isiolo | 69 600 |
| Lamu | 48 494 |