The teenager was found collapsed in Applegarth Car Park by a member of the public at 9.30pm on Saturday night.
Emergency services were called to the scene and the girl was taken to James Cook Hospital in Middlesbrough, where she tragically died.
North Yorkshire Police has launched an investigation following her death.
Early enquiries show the girl is believed to have taken MDMA and investigations are continuing.
Officers are warning anyone who has purchased the drug recently to be cautious and aware of the potential consequences of taking the drug.
Detective Inspector Jon Sygrove said: “This is an incredibly sad and tragic event and police enquiries are ongoing to determine the events around the girl’s death. Our thoughts and condolences are with her family and friends.
“As our investigation continues, I’d advise anyone who has purchased MDMA recently to be cautious about taking it. If you have already taken the drug and feel unwell, please seek medical assistance immediately.
“I’d like to appeal to the public who were in the area of Applegarth Car Park last night, who may have seen something which would assist our enquiries to come forward and make contact with the police. Please call our Force Control Room on 101, quoting reference 12190085105 and pass the information on."
A police cordon is currently in place at the car park to allow officers to conduct a thorough search of the area.