Sinead O’Connor was found unresponsive at her home in London and pronounced dead at the scene.
Her next of kin have been notified, and her death is not being treated as suspicious.
A file is now going to be prepared for the coroner.
Read more: An unapologetic singer’s rise to stardom
In a statement, the Metropolitan Police said: “Police were called at 11.18am on Wednesday 26 July to reports of an unresponsive woman at a residential address in the SE24 area.
“Officers attended. A 56-year-old woman was pronounced dead at the scene.”
O’Connor was best known for her 1990 song Nothing Compares 2 U – the track made her a global star, partly due to its iconic video.
Yesterday, her family said they were “devastated” by the death of “our beloved Sinead”.
Two weeks ago, O’Connor had told her fans that she had recently moved back to London after a 23-year absence – and she was “very happy to be home”.
She said she finishing an album that was going to be released early next year – and planned to launch a world tour spanning Australia, New Zealand, Europe and the US.
Morrissey pays tribute – and attacks music industry
On his website, former Smiths frontman Morrissey paid tribute to O’Connor – and alleged that she had been mistreated by the music industry.
“There is a certain music industry hatred for singers who don’t ‘fit in’,” he claimed.
Morrissey praised her “proud vulnerability” – describing O’Connor as someone who refused to be labelled and “had the courage to speak when everyone else stayed safely silent”.
O’Connor had a troubled childhood and spoke openly about her mental health issues.
When her teenage son Shane took his own life in 2022, she tweeted to say there was “no point living without him”, and spent time in hospital.