| Baringo | 278,154 | 215,149 | 63,005 (22.7%) | William Ruto (United Democratic Alliance) | 62.5% |
| Bomet | 376,985 | 299,594 | 77,391 (20.5%) | William Ruto (United Democratic Alliance) | 75.7% |
| Bungoma | 644,958 | 404,068 | 240,890 (37.3%) | William Ruto (United Democratic Alliance) | 39.6% |
| Busia | 414,326 | 274,686 | 139,640 (33.7%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 54.2% |
| Elgeyo Marakwet | 213,884 | 165,219 | 48,665 (22.8%) | William Ruto (United Democratic Alliance) | 74.8% |
| Embu | 332,818 | 219,783 | 113,035 (34.0%) | William Ruto (United Democratic Alliance) | 56.2% |
| Garissa | 201,129 | 109,742 | 91,387 (45.4%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 40.4% |
| Homa Bay | 550,981 | 404,031 | 146,950 (26.7%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 72.5% |
| Isiolo | 88,801 | 58,435 | 30,366 (34.2%) | William Ruto (United Democratic Alliance) | 36.1% |
| Kajiado | 460,939 | 307,034 | 153,905 (33.4%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 34.3% |
| Kakamega | 841,795 | 502,849 | 338,946 (40.3%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 42.4% |
| Kericho | 427,448 | 334,074 | 93,374 (21.8%) | William Ruto (United Democratic Alliance) | 74.5% |
| Kiambu | 1,275,008 | 825,163 | 449,845 (35.3%) | William Ruto (United Democratic Alliance) | 47.6% |
| Kilifi | 584,711 | 283,710 | 301,001 (51.5%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 34.8% |
| Kirinyaga | 368,548 | 255,926 | 112,622 (30.6%) | William Ruto (United Democratic Alliance) | 58.9% |
| Kisii | 633,491 | 400,548 | 232,943 (36.8%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 41.6% |
| Kisumu | 606,391 | 430,319 | 176,072 (29.0%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 69.2% |
| Kitui | 532,578 | 328,956 | 203,622 (38.2%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 44.2% |
| Kwale | 328,052 | 178,999 | 149,053 (45.4%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 38.3% |
| Laikipia | 260,106 | 167,315 | 92,791 (35.7%) | William Ruto (United Democratic Alliance) | 45.3% |
| Lamu | 81,453 | 50,068 | 31,385 (38.5%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 32.1% |
| Machakos | 682,254 | 406,759 | 275,495 (40.4%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 44.3% |
| Makueni | 476,504 | 289,321 | 187,183 (39.3%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 47.9% |
| Mandera | 216,808 | 135,385 | 81,423 (37.6%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 48.9% |
| Marsabit | 166,912 | 114,894 | 52,018 (31.2%) | William Ruto (United Democratic Alliance) | 35.2% |
| Meru | 766,805 | 502,835 | 263,970 (34.4%) | William Ruto (United Democratic Alliance) | 51.7% |
| Migori | 468,330 | 347,204 | 121,126 (25.9%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 62.7% |
| Mombasa | 623,239 | 268,905 | 354,334 (56.9%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 25.1% |
| Murang'a | 620,929 | 420,309 | 200,620 (32.3%) | William Ruto (United Democratic Alliance) | 55.3% |
| Nairobi | 2,357,465 | 1,308,987 | 1,048,478 (44.5%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 31.8% |
| Nakuru | 1,053,277 | 685,173 | 368,104 (34.9%) | William Ruto (United Democratic Alliance) | 43.2% |
| Nandi | 404,827 | 306,410 | 98,417 (24.3%) | William Ruto (United Democratic Alliance) | 69.1% |
| Narok | 398,784 | 308,396 | 90,388 (22.7%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 40.0% |
| Nyamira | 323,283 | 208,651 | 114,632 (35.5%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 39.9% |
| Nyandarua | 360,612 | 240,259 | 120,353 (33.4%) | William Ruto (United Democratic Alliance) | 52.5% |
| Nyeri | 478,845 | 324,802 | 154,043 (32.2%) | William Ruto (United Democratic Alliance) | 56.6% |
| Samburu | 100,014 | 70,323 | 29,691 (29.7%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 41.7% |
| Siaya | 533,409 | 376,189 | 157,220 (29.5%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 69.4% |
| Taita Taveta | 180,454 | 110,591 | 69,863 (38.7%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 44.6% |
| Tana River | 138,294 | 91,535 | 46,759 (33.8%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 36.4% |
| Tharaka Nithi | 229,999 | 160,355 | 69,644 (30.3%) | William Ruto (United Democratic Alliance) | 62.6% |
| Trans Nzoia | 398,013 | 249,736 | 148,277 (37.3%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 33.1% |
| Turkana | 236,014 | 141,918 | 94,096 (39.9%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 40.2% |
| Uasin Gishu | 503,307 | 348,128 | 155,179 (30.8%) | William Ruto (United Democratic Alliance) | 54.0% |
| Vihiga | 310,043 | 184,324 | 125,719 (40.5%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 37.0% |
| Wajir | 206,367 | 133,372 | 72,995 (35.4%) | Raila Odinga (Azimio la Umoja–One Kenya Coalition Party) | 40.4% |
| West Pokot | 219,989 | 173,564 | 46,425 (21.1%) | William Ruto (United Democratic Alliance) | 50.0% |