Police said the 25-year-old attending the event was taken to Warrington Hospital after falling ill on Friday.
She later died in the early hours of Tuesday.
Superintendent Sarah Heath, who led the policing operation for Creamfields 2022, said: “The tragic death of a young woman is heart-breaking and our thoughts are with her family and friends at this difficult time.
“An investigation into the cause of her death is under way but at this stage there is nothing to suggest that there are any suspicious circumstances.”
The woman’s next of kin have been informed.
Death of 16-year old at Leeds Festival
The news follows confirmation of a 16-year-old boy’s death after falling ill at Leeds Festival this weekend.
Leeds Festival police suspect was drug-related has been named, as his family paid tribute to him as “fiercely independent”.
David Celino fell ill while at the music event on Saturday and was taken to hospital where he died in the early hours of Sunday, West Yorkshire Police said.
Officers are investigating whether the teenager, from Worsley in Greater Manchester, had taken a particular type of ecstasy (MDMA) tablet before his death.
In a tribute released through the force, his family said: “Our David was a beautiful, fiercely independent and warm character who lived every day at 110% and who loved to spend time enjoying music with his friends.
“He had just received fabulous GCSE results, got into college, and had hoped to study computer science at a top university.
“Leeds Festival was the highlight of his summer; ultimately it was to take his life in the most unfair, cruel and horrible way, and we are broken.”
Assistant Chief Constable Catherine Hankinson previously urged anyone with information to contact police, call 101, or visit the West Yorkshire Police website.
She said: “While the exact cause of his death is yet to be established, one line of inquiry is that he had taken a particular type of ecstasy (MDMA) tablet, which was described as a grey or black oblong shape.
“At this moment in time this is believed to be an isolated incident as we have not received any similar reports.”
Those behind the festival said they were “working closely” with police to help with their investigation and that they “take all reports of incidents where drug use is suspected seriously”.