Kisumu County is one of Kenya’s 47 counties, specifically County 042. The County is not only a county but also a town in Kenya, as well as a city, and the third-largest urban center in Kenya. Similar to other counties, postal codes in Kisumu County remain relevant for sorting and delivering mail. The postal code for Kisumu is 40100, but this code belongs to the Kisumu General Post Office, which the Postal Corporation of Kenya still manages along with other postal offices in the County.
Kisumu County is located in the former Nyanza Province. It has a population of over 1,155,574 residents and covers a land area of 2,085.9 square kilometers. The County of Kisumu borders Siaya County to the West, Vihiga County to the North, Nandi County to the northeast, Kericho County to the East, Nyamira County to the South, and Homa Bay County to the southwest.
Kisumu County at a Glance
| Parameter | Details |
| County Code | 42 |
| Capital City | Kisumu City |
| Population (2019 Census) | 1,155,574 |
| Population (2025 Projection) | 1,299,840 (Projected based on 2.2% national intercensal growth rate) |
| Land Area | 2,085.9 sq km |
| Water Area | 567 sq km |
| Population Density (2019) | 554 persons per sq km |
| Number of Sub-Counties | 8 |
| Number of Constituencies | 7 |
| Number of Wards | 35 |
| Governor (as of June 2025) | Prof. Anyang’ Nyong’o |
| Senator (as of June 2025) | Prof. Tom Ojienda |
| Woman Representative (as of June 2025) | Dr. Ruth Odinga |
| GDP (Nominal, 2024 est.) | $2.672 billion USD |
| Key Economic Activities | Fishing, Sugarcane Farming, Rice Farming, Light Industry, Trade, Tourism |
Below is a full map of Kisumu County:
County Administrative Structure & Postal Organization
Kisumu County governance is based on cooperation between both the national and county governments through a devolution framework that aims to bring services closer to the People of Kisumu County. As of 2025, Kisumu has eight sub-counties but only seven constituencies, as shown in the table below:
| No. | Sub-County | Headquarters | Area (sq km) | Population (2019) | Constituency/ies |
|---|---|---|---|---|---|
| 1 | Kadibo | Rabuor | – | – | Nyando (Partial) |
| 2 | Kisumu Central | Kisumu City | 36.8 | 174,145 | Kisumu Central |
| 3 | Kisumu East | Holo | 141.6 | 220,997 | Kisumu East |
| 4 | Kisumu West | Ojolla | 209.0 | 172,821 | Kisumu West |
| 5 | Muhoroni | Muhoroni | 657.5 | 154,116 | Muhoroni |
| 6 | Nyakach | Pap Onditi | 326.7 | 150,320 | Nyakach |
| 7 | Nyando | Awasi | – | – | Nyando (Partial) |
| 8 | Seme | Kombewa | 267.7 | 121,667 | Seme |
What is the postal code of Kisumu?
The Postal Code for Kisumu County is 40100. These postal codes belong to the Kisumu GPO, but the county still has postal offices in several regions with different postal codes and PO Box numbers. Posta Kenya provides up to 19 Postal offices in Kisumu county with postal codes as follows:
| No. | Location Name (Official) | Type | Sub-County | Constituency | Postal Code |
|---|---|---|---|---|---|
| 1 | Ahero | Town/Market | Nyando | Nyando | 40101 |
| 2 | Awasi | Town/Market | Nyando | Nyando | 40122 |
| 3 | Chemelil | Town | Muhoroni | Muhoroni | 40116 |
| 4 | Dago | Market/Centre | Kisumu West | Kisumu West | 40112 |
| 5 | Fort Ternan | Town | Muhoroni | Muhoroni | 40104 |
| 6 | Holo | Centre | Kisumu East | Kisumu East | 40100 |
| 7 | Kibigori | Town/Market | Muhoroni | Muhoroni | 40119 |
| 8 | Kibos | Town/Centre | Muhoroni | Muhoroni | 40100 |
| 9 | Kisumu City | City | Kisumu Central | Kisumu Central | 40100 |
| 10 | Kombewa | Town | Seme | Seme | 40102 |
| 11 | Kondele | Urban Area | Kisumu Central | Kisumu Central | 40103 |
| 12 | Koru | Town | Muhoroni | Muhoroni | 40104 |
| 13 | Maseno | Town | Kisumu West | Kisumu West | 40105 |
| 14 | Miwani | Town | Muhoroni | Muhoroni | 40106 |
| 15 | Muhoroni | Town | Muhoroni | Muhoroni | 40107 |
| 16 | Ojolla | Centre | Kisumu West | Kisumu West | 40100 |
| 17 | Pap Onditi | Town | Nyakach | Nyakach | 40111 |
| 18 | Rabuor | Town/Market | Kadibo | Nyando | 40132 |
| 19 | Sondu | Town | Nyakach | Nyakach | 40108 |
Other popular postal facilities for governmental facilities, educational centers, and healthcare centers within Kisumu County are as follows:
| No. | Name (Official) | Type/Level | Sub-County | Constituency | Postal Code |
|---|---|---|---|---|---|
| 1 | County Assembly of Kisumu | Government Office | Kisumu Central | Kisumu Central | 40100 |
| 2 | County Government of Kisumu HQ (Prosperity House) | Government Office | Kisumu Central | Kisumu Central | 40100 |
| 3 | IEBC Central Nyanza Regional Office | Government Office | Kisumu Central | Kisumu Central | 40100 |
| 4 | Kadibo Sub-County Commissioner’s Office | Government Office | Kadibo | Nyando | 40132 |
| 5 | Kisumu Central Sub-County Commissioner’s Office | Government Office | Kisumu Central | Kisumu Central | 40100 |
| 6 | Kisumu East Sub-County Commissioner’s Office | Government Office | Kisumu East | Kisumu East | 40100 |
| 7 | Kisumu West Sub-County Commissioner’s Office | Government Office | Kisumu West | Kisumu West | 40100 |
| 8 | Lake Basin Development Authority | Government Office | Kisumu West | Kisumu West | 40100 |
| 9 | Muhoroni Sub-County Commissioner’s Office | Government Office | Muhoroni | Muhoroni | 40116 |
| 10 | Nyakach Sub-County Commissioner’s Office | Government Office | Nyakach | Nyakach | 40118 |
| 11 | Nyando Sub-County Commissioner’s Office | Government Office | Nyando | Nyando | 40101 |
| 12 | Seme Sub-County Commissioner’s Office | Government Office | Seme | Seme | 40102 |
| 13 | Ahero Girls High School | Secondary School | Nyando | Nyando | 40101 |
| 14 | Jaramogi Oginga Odinga University of Science & Technology (Kisumu Campus) | University | Kisumu Central | Kisumu Central | 40100 |
| 15 | Kisumu Girls High School | Secondary School | Kisumu Central | Kisumu Central | 40100 |
| 16 | Kisumu National Polytechnic | Polytechnic | Kisumu Central | Kisumu Central | 40100 |
| 17 | Maseno School | Secondary School | Kisumu West | Kisumu West | 40105 |
| 18 | Maseno University (Main Campus) | University | Kisumu West | Kisumu West | 40105 |
| 19 | Maseno University (Kisumu City Campus) | University | Kisumu Central | Kisumu Central | 40100 |
| 20 | Nyabondo Boys High School | Secondary School | Nyakach | Nyakach | 40118 |
| 21 | Nyabondo Girls High School | Secondary School | Nyakach | Nyakach | 40118 |
| 22 | Ahero Sub-County Hospital | Level 4 Hospital | Nyando | Nyando | 40101 |
| 23 | Jaramogi Oginga Odinga Teaching & Referral Hospital | Level 6 Hospital | Kisumu Central | Kisumu Central | 40100 |
| 24 | Kenya Medical Research Institute (KEMRI), Kisumu | Research Facility | Kisumu West | Kisumu West | 40100 |
| 25 | Kisumu County Hospital | Level 5 Hospital | Kisumu Central | Kisumu Central | 40100 |
| 26 | Kombewa Sub-County Hospital | Level 4 Hospital | Seme | Seme | 40102 |
| 27 | Maseno Mission Hospital | Level 4 Hospital | Kisumu West | Kisumu West | 40105 |
| 28 | Muhoroni Sub-County Hospital | Level 4 Hospital | Muhoroni | Muhoroni | 40106 |
| 29 | Nyakach Sub-County Hospital | Level 4 Hospital | Nyakach | Nyakach | 40118 |
| 30 | Rabuor Sub-County Hospital | Level 4 Hospital | Kadibo | Nyando | 40132 |
Frequently Asked Questions (FAQ)
What is the main postal code for the county headquarters in Kisumu City?
40100 assigned to the Kisumu GPO (General Post Office).
How many sub-counties are in Kisumu County?
Kisumu County is officially divided into eight sub-counties: Kisumu Central, Kisumu East, Kisumu West, Seme, Muhoroni, Nyakach, Nyando, and the newly established Kadibo.
What is the postal code for Maseno?
The official postal code for Maseno town, which is home to Maseno University and Maseno School, is 40105.