Belfast councillor Micky Murray has requested an urgent meeting between council officers and representatives from Emerge festival following the death of a teenage girl at the weekend.
The Alliance Party representative said festivals are meant to be “safe spaces”.
Two other people were taken to hospital after becoming ill at the same event at Boucher Playing Fields.
A woman in her 30s remains in hospital in a serious but stable condition, while a teenage boy has received treatment and is expected to make a full recovery.
Police said enquiries are ongoing after a teenage girl died in hospital after becoming unwell at the Emerge music festival in south Belfast on Sunday.
Emerge, an electronic music festival, took place at Boucher Playing Fields on Saturday and Sunday, with more than 40,000 people in attendance.
In a statement, Murray said his “sincere condolences are with the loved ones of the young individual who has tragically lost their life in these circumstances”.
He urged people “not to speculate” while police enquiries are ongoing.