The singer who endured a difficult childhood, where she spoke about being subjected to physical abuse at the hands of her mother, came to prominence following her cover of the track 'Nothing Compares 2 U' in 1990.
Having released her debut album 'The Lion And The Cobra' three years earlier, her cover of 'Nothing Compares 2 U' which was written by Prince, saw O'Connor win several Grammy Awards, as well as being named artist of the year by Rolling Stone Magazine.
Overall, Sinead O'Connor wrote 10 solo albums, as well as songs for films, and collaborated with other artists.
Sinead O'Connor was also known for public outburst, including tearing up a picture of Pope John Paul II, during an appearance on Saturday Night Live, in protest against the Catholic Church's child abuse scandal.
The singer has also been outspoken about her mental issues, including being diagnosed with bipolar and having suicidal thoughts.
O'Connor has endured a difficult time recently, following the tragic death of her son Shane to suicide last year.
Following her death, tributes were paid to the singer, from musicians and political figures including Taoiseach Leo Varadkar and President Michael D Higgins.
"Really sorry to hear of the passing of Sinéad O’Connor", Varadkar wrote. "Her music was loved around the world and her talent was unmatched and beyond compare. Condolences to her family, her friends and all who loved her music.Ar dheis Dé go Raibh a hAnam".
Canadian singer Bryan Adams also shared this touching tribute to O'Connor, "RIP Sinéad O'Connor, I loved working with you making photos, doing gigs in Ireland together and chats, all my love to your family".
Check it out and more below.