The suspected overdose deaths of five young people in as many months at music festivals in NSW are to come under the judicial microscope next week as the Coroner's Court conducts a public hearing into the high-profile cluster of fatalities.

NSW Premier Gladys Berejiklian has welcomed an inquest into the spate of deaths, as well as any recommendations that arise from such an inquiry, while drug reform advocates are calling for pill testing to be discussed as part of a raft of harm minimisation measures in the proceedings.

Alex Ross-King is the fifth young person to die at a music festival in recent months. Credit:Facebook

Acting State Coroner Teresa O'Sullivan will hold a directions hearing at the Coroner's Court in Glebe on January 22, 10 days after Central Coast woman Alex Ross-King, 19, died in hospital after attending the FOMO music festival in Parramatta.

Ms Ross-King's death followed that of Josh Tam, 22, who died after taking a substance at the Lost Paradise festival on the Central Coast on December 29; 19-year-old Callum Brosnan, who died after attending the Knockout Games of Destiny at Sydney Olympic Park on December 8; and Joseph Pham, 23, and Diana Nguyen, 21, who died at Defqon.1 in Penrith on September 15.