Ndingi was born in the Mwala location in then
Machakos district in colonial
Kenya. He joined Kiserian Seminary after completing his primary school education. Ndingi sat for the Cambridge School Certificate privately and returned excellent results. He was then admitted to
St. John Fisher College in New York, USA, where he pursued a
BA degree in political science and history. He was ordained as a priest in 1961 and served under
Archbishop J. J. McCarthy of the Nairobi diocese. He was ordained as a bishop in 1969 and served in that capacity in the dioceses of Machakos and Nakuru before being appointed as Coadjutor Archbishop of Nairobi in 1996 as an assistant to Cardinal
Maurice Michael Otunga. He succeeded Cardinal Otunga on 21 April 1997 as the Archbishop of Nairobi. He was retired by
Pope Benedict XVI on 6 October 2007 after attaining the age of 75 years. He was succeeded by the current Cardinal
John Njue who was his assistant in Nakuru. ==Struggle for multiparty democracy==