Clarke attended Saint Mary's College, winning an Island Scholarship in Mathematics in 1938.
Disagreements with the new National Alliance for Reconstruction government resulted in Clarke's decision not to seek a third term.
A private funeral was held at the Church of the Assumption on Maraval Road in Port of Spain.
It was an inter-religious celebration at which the President, Prime Minister and Chief Justice paid tributes.
Sir Ellis' coffin, draped in a Trinidad and Tobago flag, was set atop a cannon and pulled by a military vehicle.