The singer was best known for her 1990 song Nothing Compares 2 U – the track made her a global star, partly due to its iconic video.
It comes a year after the mother-of-four’s son Shane, 17, took his life in January 2022 after escaping hospital while on suicide watch.
A family statement said: “It is with great sadness that we announce the passing of our beloved Sinead.
“Her family and friends are devastated and have requested privacy at this very difficult time.”
The singer had changed her name to Shuhada’ Sadaqat in 2018 when she converted to Islam.
In her last Tweet, O’Connor posted a photo of Shane and said: ‘Been living as undead night creature since. He was the love of my life, the lamp of my soul.
Ms O’Connor was presented with the inaugural award for Classic Irish Album at the RTÉ Choice Music Awards earlier this year.
Sinéad is survived by her three children, Jake, 36, Roisin, 27, and Yeshua, 16.
No further details about her death have been disclosed.
Hailing from the emerald shores of Ireland, O’Connor surged to musical eminence in the late ’80s, with her debut album “The Lion and the Cobra” enchanting critics and listeners alike. Her soul-stirring melodies and emotive verses defied convention, paving the way for an illustrious career.
O’Connor’s timeless rendition of Prince’s “Nothing Compares 2 U” catapulted her to global stardom, earning her accolades and a permanent spot in the hearts of music aficionados worldwide.
Yet, behind the mesmerizing melodies, O’Connor was a fervent advocate for social and political change. Fearlessly using her platform to address sensitive issues, she was no stranger to controversy, but her resilience in the face of adversity made her a beacon of authenticity.
Sinead O’Connor’s musical legacy and unwavering commitment to her principles will echo towards. The world has lost a melodic maverick, but her songs will last forever.