Wanjiku is a feminine Kenyan name. Historically, Wanjiku was one of the nine daughters of the man and wife who founded the Agikuyu people, Gikuyu and Mumbi. Consequently, the descendants of her lineage form the Agaciku Clan of the Agikuyu tribe in Kenya.
In Kikuyu traditions, the name Gathigia was also the same as Wanjiku. For instance; this happened in cases where the person after whom a child was to be named bears the same name and it existed earlier like if the mother of the husband is called Wanjiku and wife's mother is Wanjiku. The first daughter will be named Wanjiku after her fathers mother according to the naming tradition. The second daughter would also be named Wanjiku after her mothers mother, according to the naming tradition, but since it is inconvenient to have two daughters with the same name, the second daughter bore the name Gathigia just for distinction. The true name of the daughter Gathigia may be believed to be Wanjiku, so when she had granddaughters which are supposed to be named after her they may be named Wanjiku rather than Gathigia. However, this trend has changed with time and Gathigia is no longer a common name. Ciku is a common short form of Wanjiku.
Today, in Kenya, Wanjiku is a name that is used to symbolize the average citizen in the context of national politics. The name came to represent the ordinary person "Mwananchi" after former President Daniel arap Moi dismissed the calls for a new constitution. He said "Do you think Wanjiku understands what is a constitution?" Following this, 'Wanjiku' came to mean the general public and the meaning has stuck.