Fianna Fáil leader Micheál Martin said Dr Garret FitzGerald made an enormous contribution to Irish politics and to our wider society.
Mr Martin described the late former taoiseach as a hard-working politician of compassion and ability, a prolific journalist of insight and understanding, and a brilliant academic of versatility and knowledge.
He paid tribute to his work in the peace process, saying Dr FitzGerald was a strong advocate of peace in the North.
"He was an implacable opponent of those who espoused violence as a means to a lasting political solution on this island and he worked sincerely towards building an Ireland free of conflict," Deputy Martin said.
"Though my party did not necessarily agree with Garret on every political issue, I greatly admired his integrity, his abilities and his unfailing politeness and courtesy.
"He was a person who cared deeply about Ireland and he has given distinguished and patriotic service to our people."