The former Bishop of Derry and Raphoe died at the age of 79 at Letterkenny Hospital in his native Donegal on Friday following an illness.
Dr Hegarty, who was born in Kilcar, led the diocese of Derry from 1994 to 2011, before retiring due to ill health.
Derry-born Archbishop Eamon Martin expressed his sadness, recalling Dr Hegarty’s dedication to helping Irish emigrants and their families, as well as his passion for education and efforts to nurture the peace process.
“I am saddened to hear of the death of Bishop Séamus Hegarty.
“The news came during a meeting of the Irish bishops and we prayed for the happy repose of his soul and for the comfort of his family and close friends.
“Speaking as President of the Irish Catholic Bishops’ Conference, I wish to acknowledge the contribution of Bishop Hegarty to the work and outreach of the Conference over thirty years – first as Bishop of Raphoe, and then as Bishop of Derry.
“He was an active member of the Commission for Education in NI and on the Council for European Affairs, but what stands out is his dedication to the plight of Irish emigrants and their families, and his response to Irish prisoners overseas.
“Bishop Hegarty often intervened at conference meetings to draw attention to the personal, social and economic challenges facing emigrants, and he supported efforts to raise vital funds for the mission to those who face challenges far from home.“On a more personal level, I am grateful to Bishop Séamus for his encouragement and support to me as my bishop in Derry from 1994 until his retirement in 2011.
“He was unstinting in his support for my role as teacher and President of Saint Columb’s College.
“Having been a school principal himself for many years, he was passionate about the importance of education for young people and he had a strong awareness of the issues facing school staff and managers.
“He worked tirelessly to secure the new school sites for girls’ post-primary education in the City of Derry and to ensure that the very best facilities were being made available for our young people.
“When he came to Derry, he often spoke lovingly of his native Donegal, yet he quickly made many friends among the parishioners of the Diocese of Derry, including among the Irish language community – he was a native speaker himself.
“Bishop Séamus was strongly pro-life and he was always anxious as a faith leader to nurture the fledgling peace process.
“On behalf of the Bishops’ Conference I express my sympathies to the family of Bishop Hegarty, to Josie, his beloved housekeeper and carer, to the priests of the Diocese of Derry and to Bishop Donal McKeown as well as to his many friends in Raphoe Diocese.
“I invite the faithful to pray for the repose of Bishop Hegarty’s soul at this time.
“Ar dheis Dé go raibh a anam.”
Meanwhile former Church of Ireland bishop Ken Good added his tribute to Dr Hegarty.
“A former teacher, like myself, he led his two dioceses, Raphoe and Derry, at a very difficult time in the history of the Roman Catholic Church in Ireland.
“I, more than most, am aware of how challenging church leadership can be – at whatever point in history and whatever one’s denomination,” he said.
Dr Hegarty became embroiled in controversy at one stage over his response to the issue of clerical child abuse.
He apologised for historical poor practice.
“I am deeply sorry that anyone was hurt through my management of allegations historically,” he stated in 2011.