A statement from Ms Brennan’s family said she died peacefully surrounded by loved ones in her native Co Donegal.
Ms Brennan’s brothers and members of Clannad, Pól and Ciarán, said they were heartbroken at the loss of their sister.
In a tribute posted online, they said: “We are completely heartbroken at the passing of our dearest sister Máire (Moya).
“She crossed over last night at home in Donegal surrounded by family and has now joined Pádraig and Noel across the veil.
“Her voice was the signature sound of Clannad and will live on forever.”
Brennan is survived by her husband Tim and her children Aisling and Paul.
Ms Brennan’s remains will repose at her home at Upper Dore, Gweedore, on Wednesday, April 15 and on Thursday, April 16 from 1pm to 8pm.
Prayers willl be nightly at 8pm.
The house will be private after the prayers and on the morning of the funeral.
Ms Brennan’s Funeral Mass will take place on Friday, April 17 at 2pm in St. Patrick’s Church, Meenaweal, Crolly with interment afterwards in Magheragallon Cemetery Gweedore.
The Funeral Mass can be viewed live on Kieran Roarty Funeral Director’s Facebook page and on the Church webcam via MCN Media.
Born Máire Ní Bhraonáin in 1952 to her parents Leo and Máire Brennan, she grew up in Gaoth Dobhair, a Gaeltacht area in the northwest of Donegal.
The eldest of nine siblings, she formed Clannad in the 1970s with her brothers Pól and Ciarán, and their uncles Noel and Pádraig Ó Dúgáin.
Brennan was the lead singer of the group and was also a songwriter and harpist.
The group started out performing at the family pub, Leo’s Tavern, before going on to huge success and international renown.
Moya on stage in 1986
News in 90 seconds – Tuesday, April 14
Clannad brought Irish music to a global audience with the success of the iconic theme tune to the TV series Harry’s Game. They went on to perform the song on Top of the Pops, becoming the first act to perform in Irish on the programme.
The song also bagged Clannad an Ivor Novello Award for Best Television Soundtrack.
Further work on music for television saw the group win a Bafta for Best Television Music for their work on Robin of Sherwood.
Clannad’s studio albums brought more awards success, including a Grammy Award for Best New Age Album for Landmarks in 1999.
Brennan’s sister Eithne Ní Bhraonáin spent a number of years performing as part of Clannad, before going on to pursue a solo career. Performing under the name Enya, she would go on to become one of the world’s best-selling musicians.
Affectionately known as the First Lady of Celtic music, Brennan also enjoyed a successful solo career in her own right.
Bono paid tribute to Brennan on behalf of U2 and said she had an “otherworldly voice”.
“She sang like an angel,” he told the Irish Independent.
“She walked through this world like an angel, and now she’s back with her own kind.
“We love you Moya.”
Donegal Sinn Féin TD Pearse Doherty paid tribute to Brennan on Tuesday morning, saying he was “very sad” to hear the news of her passing.
“Moya gave so much to Ireland and its people. Known as the First Lady of Celtic music, her songs and stories shaped so many lives and will always be cherished,” Mr Doherty wrote in a post on X.
“Moya was proud of her roots. A powerful ambassador for Ireland – she took our music, language and culture and shared it with the world.
“Thinking of her husband Tim, her two children Aisling and Paul, the wider family, her friends, and all those who knew and loved her.
“Ar dheis Dé go raibh a hanam.”
Fine Gael leader Simon Harris said he was deeply saddened to hear of the passing of Moya Brennan.
“Moya was a musical icon with a unique voice of extraordinary beauty,” he said.
“She went from Gweedore to global renown with Clannad, bringing Irish music to the international audience.
“Her loss will be deeply felt throughout the music and arts communities, and far beyond.”
In a tribute posted on social media, Taoiseach Micheál Martin said he is deeply saddened at the passing of Moya Brennan who was “an iconic Irish voice.”
“Along with her Clannad bandmates, Moya brought Irish folk music to the international stage.
“Deepest sympathies to Moya’s family and friends at this difficult time.
“Ar dheis Dé go raibh a hanam.”
Donegal singer Daniel O’Donnell described Ms Brennan as a ‘beautiful lady.’
“Majella and I are deeply saddened at the passing of our dear friend Moya Brennan.
“A beautiful lady who will be greatly missed by all who were blessed to know her.
“We send our sincere sympathy to her husband Tim, daughter Aisling, son Paul, her mother Baba and all the extended family at this very sad time.
“Rest in Peace Moya,” said Mr O’Donnell.
Donegal-based Mary From Dungloe International Arts Festival said Ms Brennan who was “a cherished friend and a wonderful supporter” of the festival.
The committee said her legacy will live on in her music and in the hearts of all who loved her.
“We had the great honour of welcoming her to Dungloe in 2023, where she officially opened the festival with such grace, warmth, and kindness.
“Her generosity knew no bounds.
“Moya was always willing to support the festival in any way she could, and as recently as last October, she kindly lent her voice to our promotional video; something we will treasure deeply.
“Moya’s talent was extraordinary, but it was her gentle spirit, humility, and genuine kindness that left a lasting impression on all who had the privilege of knowing her.
“We extend our heartfelt sympathies to her husband Tim, daughter Aisling, son Paul, her mother Baba, her brothers and sisters, and her wider family and friends.”
Singer Una Healy described Ms Brennan as “Ireland’s first lady of Celtic music”.
“Deeply saddened to hear of the loss of the wonderful Moya Brennan.
“I had the great pleasure of meeting and singing with Moya on a number of occasions, along with her daughter Aisling and with the Irish Women in Harmony.
“She was such a beautiful person and a legend.
“RIP Moya. My deepest sympathies to her family and friends,” said Ms Healy.
Meanwhile, Frances Black said Ms Brennan was one of the “most beautiful people” in the music industry.
“Moya was not only a wonderful musician and singer, she was a warm, generous and deeply spiritual soul who touched everyone she met.
“I had the privilege of catching up with Moya this past January after she performed at the Tradfest Women of Note gig , and we had plans to meet again in August when I would be up in Donegal.
“Moya gave so much to Irish music and to the world, her voice with Clannad was unlike anything else, a sound rooted in the Donegal Gaeltacht that somehow spoke to millions across the globe.
“But beyond the music, it was who she was as a human being that will stay with me.
“My deepest condolences to her husband Tim, her children Aisling and Paul, and all of her family at this incredibly sad time,” said Ms Black.