© N/A Bakers Park, Newton Abbot Pic: Google
The teenager was taken to hospital from Bakers Park, Newton Abbot, around 4.50am but later died in the early hours of Saturday.
Devon and Cornwall Police are investigating the circumstances of her death and believe she had taken a new psychoactive substance.
Two other teenage girls were also taken Torbay District Hospital as a precaution.
Officers want to speak to anyone with information about the incident, as well as anyone who was in the park in the early hours of Saturday.
The teenager's family have been informed of her death while police are still at Bakers Park as they conduct initial enquiries.
The Government this month unveiled a new strategy to target psychoactive substances, which were formerly known as "legal highs" before a blanket UK-wide ban came into force in May last year.
Offenders who break the new laws face up to seven years in prison.
In 2015, more than 100 deaths in the UK were linked to "legal highs".