A message her website read on Thursday: 'Bonnie's family and team are heartbroken to announce that Bonnie unexpectedly passed away last night in hospital in Portugal as a result of the illness that she was being treated for.'
The singer recently went into cardiac arrest following surgery which left her in an induced coma.
The Welsh star, who owns a property on the Algarve had been treated for emergency bowel surgery and a perforated intestine after a burst appendix.
A spokesperson for the singer confirmed at the time: 'Bonnie has been put into an induced coma by her doctors to aid her recovery. We know that you all wish her well and ask for privacy at this difficult time please.
'We will issue a further statement when we are able to.'
Bonnie Tyler has died aged 75: Singer passed away in Portugal after going into cardiac arrest following surgery which left her in an induced coma (pictured in February)
It was first reported that Bonnie had started feeling unwell in May.
She had been bedridden for two days at her Algarve home before her worried husband Robert Sullivan took her to the private hospital she was seen at before being transferred to Faro.
The singer, who has had multiple hits in her long career and competed at the Eurovision Song Contest representing the UK in 2013, is believed to have been rushed to hospital on April 30.
A day earlier, when her health woes first emerged, the spokesman had said: 'We are very sorry to announce that Bonnie has been admitted to hospital in Faro, Portugal, where she has a home, for emergency intestinal surgery.
'The surgery went well and she is now recuperating.
'We know that all of her family, friends and fans will be concerned about this news and will be wishing her well for a full and swift recovery.'
She was said to have been 'stable' in an intermediate care unit at Faro Hospital before an apparent worsening of her health led to her being transferred to intensive care.
On June 15, the singer's team said she had woken up from a medically induced coma after suffering a cardiac arrest in Portugal a month previously.
They said at the time: 'Bonnie is no longer in a coma, but remains seriously ill. Although her condition is improving, the recovery process is slow.'
Sources said she had been maintaining her professional activity in the run-up to being taken to hospital, despite complaining of persistent pain for several weeks.
Cardiac arrest is a medical emergency in which the heart suddenly and unexpectedly stops pumping blood, causing it to stop beating and disrupting oxygen flow to the body and brain.
It causes instant unconsciousness and collapse. Immediate action involving starting CPR and using a defibrillator where available is essential to prevent death.
A ruptured appendix is a severe medical emergency requiring immediate surgical intervention and antibiotics to prevent fatal infections.
When an infected appendix ruptures, it creates a hole and causes fecal matter and bacteria to leak into the abdominal cavity.
The Welsh songstress was due to start her European tour later this year.
Speaking in March, Bonnie spoke about pain she'd been having in her knees, which at the time were her only real health concerns.
The Welsh songstress was due to start her European tour later this year (pictured in 1986)
She told Hello!: 'I'm fit enough at the moment, touch wood, and I'm really enjoying doing the shows.
'I'm still rocking on that stage with my wonderful band, and if you've got your health, you've got everything.
'I do home Pilates, only 20 minutes a day - it's something I can do in my hotel rooms.
'I have had problems with my knees; I didn't have new knees, I had what they call washouts [a surgical knee procedure], which turned out to be very successful. So, hopefully that will last for a long time.'
Bonnie and property developer Robert split their time between their homes in Portugal and south Wales.
She first bought a property in the Algarve in the 1970s having fallen in love with the region while recording an album.
In 2009, she knocked down her five-bedroom villa in Albufeira to build a full-frontal glass home with elaborate garden water features.
Speaking about the area, she said: 'It's a magical place where you could sail out to sea at midnight and enjoy a barbecue and return to shore in the early hours of the morning to find the local bars still open.'
Bonnie and her husband, who is a former Olympian Judo athlete, also owned a number of rental properties in Portugal.
Speaking to the Mirror last year, she said: 'I started singing when I was 17 and I never thought I'd still be doing it at this age. I've slowed down a little bit, but I know now that I will never retire.
'Even though I was so lucky because I was in Portugal when the first lockdown was announced, by the end of it, I'd had enough. I was going crazy. I needed to get back out there on the road!'
She has had an impressive career and in 2023 was awarded an MBE for services to music.
Bonnie previously told the Daily Mail that she inherited her love of music from her mother but it took her a while to overcome her shyness to perform.
She said: 'My mother, Elsie, was a big part of why I became a singer. She had the most beautiful voice; she sounded like Maria Callas.
'I inherited her love of music. But I had no confidence. She used to say to me: 'Believe in yourself because no one else is going to do it for you.' But it took me a long time.'
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Cataluña enviará a Venezuela 15 bomberos especializados en estructura colapsadas por los terremotos
El presidente de la Generalitat, Salvador Illa, ha anunciado este viernes que enviarán a Venezuela 15 especialistas del Grupo de Estructuras Colapsadas (GREC) de Bombers y ha explicado que también han ofrecido al país un grupo de diez forenses para ayudar a la identificación de cadáveres y para que se puedan desplazar cuando lo requieran las autoridades venezolanas.
Lo ha dicho en la inauguración de la jornada 'L'impacte dels fons Next Generation a Catalunya', donde ha reiterado la "solidaridad del Govern y de todo el conjunto de la ciudadanía de Cataluña en momentos trágicos para el país", tras los dos terremotos.
Illa ha añadido que este viernes a primera hora de la tarde se reunirá con las entidades venezolanas de Cataluña: "Para interesarme por su estado y por todo lo que están pasando".