Kiambu County is located in former Central Province of Kenya. Its capital is Kiambu and its largest town is Thika. Kiambu County is the second most populous after Nairobi County. Kiambu County borders Nairobi and Kajiado Counties to the South, Machakos to the East, Murang’a to the North and North East, Nyandarua to the North West, and Nakuru to the West and has a population of 2,417,735 according to 2019 census.The county lies between latitudes -1.146188  and Longitude 36.966499.

There are several theories that explain the origin of the name Kiambu; one theory suggests that it was derived from a prominent Kikuyu clan known as mbari ya mbuu who used to live next to the current day Kiambu town. Another theory suggests the area used to experience constant showers hence the kikuyu phrase ‘kia mbuu’’ meaning the “place of drizzle.”
The third theory suggests that during the ancient times, Kikuyu’s and Maasai’s would engage in war and the screams from the area would attract the authorities, hence earning the name ‘Kia Mbuu’ meaning ‘Screams’.

Kimani Wamatangi is the governor of Kiambu county following the election win on a UDA Ticket and successful swearing-in after the 2022 General election. He is deputised by H.E. Rosemary Kirika who hails from Gatundu-North subcounty. Karungo Wathang’wa is the senator to the county while Ann Wamuratha is the woman rep after both of them being elected on UDA ticket during the general election in august 2022.

The county is 40% rural and 60% urban owing to Nairobi’s consistent growth Northwards. The Kikuyu are the dominant tribe in the county. The County is divided into twelve (12) sub-counties namely Limuru, Kikuyu, Kabete Lari, Gatundu South, Gatundu North, Githunguri, Kiambu, Kiambaa, Ruiru, Juja and Thika Town. These subcounties are further divided into 60 electoral wards. Each an every subcounty is headed by Subcounty administrator and every ward is headed by ward Admin.