Leading members of the international cricketing fraternity, the government and judiciary packed St George's Cathedral in Cape Town as Sonn was eulogised.
"It is amazing that Percy, the boy from Bellville Cricket Club, became the boss of world cricket," ICC chief executive Malcolm Speed said.
Sonn, 57, succeeded Ehsan Mani as head of the world governing body in June 2006 after two years as the organisation's vice-president.
Pall bearers into the cathedral included Zimbabwean cricket administrator Peter Chingoka and Gerald Majola, Cricket South Africa's CEO.
After the service Sonn, who leaves his wife Sandra and three children, will be cremated in a private ceremony.