Mboya was born around 1931 in Rusinga valley, Western Kenya. He had a three - year secondary education course after which he trained as a Health Inspector.
After school, he worked as a Health Inspector in Nairobi. During his work, he was greatly touched by the living conditions and welfare of the Africans. He blamed the government for inaction and indifference to the conditions of the Africans.
In 1953, he was elected Sectary General of the Kenya Federation of Labour. When political activities were banned due to the confusion created by the Mau - Mau activities, the federation remained the only forum for those who wanted to air out their grievances and discontent against the colonial government.
During his tenure of office, he established contacts with overseas Labour organisations like in the
United States and Britain. This greatly enhanced his credibility.
In 1957, he established the Peoples' Convention Party (PCP) to contest the elections to the Legislative council.
In 1958, he was elected to the Legislative council with three other African members, due to the reforms introduced in 1957 by the new Colonial Secretary, Lennox - Boyd. He became one of the vocal members on council.
He strongly 'opposed Lennox - Boyd's constitutional changes whereby the twelve specially elected members had to be chosen by the Legco. He thus led other African members into a boycott, demanded a full constitutional conference and the release of Kenyatta.
In 1960, Tom Mboya was one of the African representatives who participated in the Lancaster House conference in London. This conference gave the African majority on the unofficial side of the Legislative council.
In March 1960, Mboya with other African members to the Legco (Oginga Odinga, James Gichuru) formed the Kenya African National Union (KANU). He was elected Secretary General of this new party.
He participated in the elections of 1961 through which KANU got a resounding victory (KANU 83 seats, KADU 41 seats). However, it refused to form a government until Kenyatta was released.
With other African nationalists, Tom Mboya organized and arranged for the independence of Kenya.