Mr Collymore who died on Monday morning after a long battle with cancer was cremated on Tuesday.
Hundreds of mourners, friends and family of the late Safaricom CEO Bob Collymore arrived at the All Saints Cathedral on Thursday for his memorial service.
President Uhuru Kenyatta, the First Lady Margaret, Deputy President William Ruto, Britain's former Prime Minister Tony Blair, former vice-presidents Moody Awori, Musalia Mudavadi and Kalonzo Musyoka were among scores of dignitaries who attended the memorial service.
Other leaders at the service included Cabinet secretaries Joe Mucheru and Adan Mohammed and politicians, among them, Baringo Senator Gideon Moi, Makueni Governor Kivutha Kibwana and Machakos Governor Alfred Mutua.
A constellation of artists, politicians and business leaders thronged the All Saints Cathedral for Collymore's final send-off.
Former Vision 2030 boss Mugo Kibati, Kenya Commercial Bank's Joshua Oigara and industrialist Manu Chandaria were also among the mourners at the church.
Ms Beth Mugo, a nominated senator and a cancer survivor, who was also in attendance, described the late Collymore as a good friend whose outstanding work as CEO of one of the leading companies in Kenya improved the life of many Kenyans.
Ms Mugo noted that more cancer treatment specialists, trainers and nurses are needed in the country as the scourge bites.
Mr Awori described the former Safaricom CEO as a man who was dedicated to serving Kenyans without discrimination.
Performing artist Nameless said that Mr Collymore hugely contributed towards the development of the local music industry through initiatives such as Safaricom Live and Skiza tunes.
Mr Mudavadi said Collymore has left a big shoe but urged the firm to consider a Kenyan for the chief executive job.