"There can be few Irish people of his generation, or of any other generation, who have contributed as much to improving the lives of so much of humanity," said Tom Arnold, chief executive of the Concern charity that Finucane spent decades promoting.
Arnold said the priest saved countless lives and would be mourned by tens of thousands around the world.
Finucane was a priest in the Spiritan Fathers order in Nigeria during its 1967-1970 civil war with the breakaway state of Biafra. Determined to combat famine as the Nigerian military crushed the rebellion, he worked with Dublin-based workers to channel aid to Biafra through its often-shelled airstrip and by cargo ship.
That aid effort, initially known as Concern Africa, shortened its name to Concern in 1970 as it gained ambitions to provide food, medical support and education in many of the world's poorest countries.
Finucane became Concern's senior official in Bangladesh in 1972 following its war of independence from Pakistan.
He served as the charity's chief executive from 1981 to 1997, and later was its honorary president responsible for spearheading fund-raising in the United States.
During Finucane's time as chief executive, Concern expanded aid work into 11 countries and dramatically increased its fund-raising. Today the charity is one of Ireland's biggest, with operations in 18 countries in Africa and 10 in Asia, including Afghanistan and North Korea.
"He used his great gifts of personality and charismatic leadership to work for the things he believed in. People loved to be with him and he loved to be with people. He inspired a whole generation of Concern overseas volunteers," Arnold said.
Finucane, who was born in the western Irish city of Limerick, died Tuesday morning at the Spiritan Fathers' residence for retired priests following a short unspecified illness. He is survived by three brothers and two sisters. Funeral arrangements were not announced.
On the Net: