President of Ireland Michael D. Higgins has led tributes to Irish singer Sinéad O'Connor, whose family confirmed her death on Wednesday, July 26. 

Higgins said he was struck by O'Connor's "fearless commitment" to important issues that she brought to public attention, "no matter how uncomfortable those truths may have been."

"My first reaction on hearing the news of Sinéad’s loss was to remember her extraordinarily beautiful, unique voice. What was striking in all of the recordings she made and in all of her appearances was the authenticity of the performance, while her commitment to the delivery of the song and its meaning was total," Higgins also said in the statement. 

Dozens of Irish and international celebrities also paid tribute to O'Connor following the announcement of her death on Wednesday evening. 

"Sinead I love you and I hope you are at peace," Shane MacGowan, frontman for the Pogues, said on Twitter, sharing an earlier post from his wife Victoria Mary Clarke.

❤️❤️❤️❤️❤️ Sinead I love you and I hope you are at peace https://t.co/lXg1kmYGRh

— Shane MacGowan (@ShaneMacGowan) July 27, 2023

U2 paid tribute by sharing pictures and lyrics from O'Connor's song "Heroine."

Touch these eyes with a broken smile, Touch my mouth with your furrowed brow, Lift my heart, heal my shame , Lead me into rest again .. Heroine.. Rest In Peace Sinéad. pic.twitter.com/QwIpa0Splu

— U2 (@U2) July 27, 2023

Irish singer Mary Black described O'Connor as a "leader" for young Irish artists and added that she meant every word she ever sang. 

"She sang with such truth. Every word she sang in any song, you felt she meant it from the bottom of her heart," Black told RTÉ's Morning Ireland on Thursday. 

"She had that sort of brilliant, raw talent that came out no matter what song she sang." 

Fellow Irish singer Imelda May shared a picture of her and O'Connor, writing "can’t find the words yet."

The legend Sinead O’Connor is gone.
My dear friend, my mate, my sister
Can’t find the words yet
Tá mo chroí briste.#SineadOConnor pic.twitter.com/9Oy8oPBrK5

— Imelda May (@ImeldaOfficial) July 27, 2023

Patrick Kielty, the new host of RTE's "The Late Late Show," said O'Connor "was the truth way before most of us knew where to look."

Just heartbreaking. She was the truth way before most of us knew where to look. Rest in peace, Sinéad. pic.twitter.com/Eny5ShsZMw

— Patrick Kielty (@PatricKielty) July 26, 2023

Irish author Marian Keyes said O'Connor was an "amazing, brave, beautiful, unique wonder," while comedian Dara Ó Briain said he hoped O'Connor realized how much she was loved. 

Sinn Féin President Mary Lou McDonald said she was "deeply saddened" to learn of O'Connor's death, describing her as an "iconic musical talent" and a "voice of spell-binding beauty."

"Captivating. passionate, fearlessly outspoken. She was a once-off. My heartfelt condolences to her family + friends this evening. Codladh Sámh," McDonald said on Twitter. 

Elsewhere, Canadian musician Bryan Adams spoke of how he "loved" working with O'Connor, recalling the chats he had with her and the gigs they had performed together. 

Cat Stevens described O'Connor as a "gentle soul," while American rapper Ice T praised O'Connor, saying "She stood for something… Unlike most people…. Rest Easy."

Smashing Pumpkins singer Billy Corgan paid tribute to O'Connor in a post on Instagram, praising her for her "act of simple resistance" when she ripped up a picture of Pope John Paul II on SNL in 1992. 

"She was talented in ways I'm not sure she completely understood. But Sinéad stands alone as a figure from our generation who was always true to the piercing voice within and without. And for that, I will always admire and respect her," Corgan wrote on Instagram.

"And never forget that she was once canceled for an act of simple resistance. Her crime? Tearing up a photo."

Canadian songstress Alanis Morissette shared a picture of O'Connor with a broken heart emoji.

💔 pic.twitter.com/vHCgsVTvKQ

— Alanis Morissette (@Alanis) July 26, 2023

Oscar-winning actor Russell Crowe described O'Connor as an "amazing woman" and recalled meeting her during a visit to Ireland last year. 

"In a conversation without fences we roamed through the recent Dublin heatwave, local politics, American politics, the ongoing fight for indigenous recognition in many places, but particularly in Australia, her warm memory of New Zealand, faith, music, movies and her brother the writer," Crowe said.  

"I had the opportunity to tell her she was a hero of mine." 

O'Connor's family confirmed her death in a statement on Wednesday evening. 

"It is with great sadness that we announce the passing of our beloved Sinéad,” her family said in a statement on Wednesday, according to RTE.

“Her family and friends are devastated and have requested privacy at this very difficult time."

In a statement on Thursday, UK police announced that O'Connor was found unresponsive at her London home and pronounced dead at the scene. 

The metropolitan police said O'Connor's death is not being treated as suspicious. 

The statement said officers responded to reports of an unresponsive woman at an address in southeast London shortly before noon on Wednesday. 

A file is being prepared for the coroner's office.

Born in Glenageary in Dublin, O'Connor released 10 studio albums and reached international stardom following the release of her second album "I Do Now Want What I Haven't Got" in 1990, which includes the smash-hit single "Nothing Compares 2 U."

The single earned O'Connor several Grammy nominations, but she announced a boycott of the ceremony, citing the excessive commercialism of the music industry.

O'Connor frequently took a stand on issues such as women's rights and child abuse, no matter the consequences. 

In 1992, she faced significant backlash for ripping up a photograph of Pope John Paul II and telling people to "fight the real enemy" during an appearance on SNL. She was loudly booed while performing at a Bob Dylan 30th anniversary concert in Madison Square Garden two weeks later. 

O'Connor is survived by her three children, Jake, Yeshua, and Roisin. Her 17-year-old son Shane died in January 2022. 

In one of her last tweets, O'Connor said she is "lost in the bardo without him."