The mass for Retired Catholic Archbishop Ndingi Mwana a'Nzeki, who died last week aged 89, is being held at the Holy Family Basilica in Nairobi.
He is set to be buried in a private ceremony later today, the church had announced.
Only about 100 people will be allowed to the ceremony, locking out politicians and even Catholic clergy and faithful, whom the late archbishop mentored and led for more than 60 years in priesthood.
Mwana a'Nzeki was born on December 25, 1930 in Machakos.
He was consecrated bishop by Pope Paul VI.
He served in the dioceses of Machakos (1969-1971) and Nakuru (1972-1996).
In 1996 he was made the coadjutor of the Archdiocese of Nairobi in 1997.
Mwana a'Nzeki later became the archbishop of Nairobi in 1997 where he served until his retirement in 2007.