The boy, now 17, allegedly used a hunting knife to attack Harry during an altercation in the famous park just before midnight last December.
Appearing at the Old Bailey via videolink from custody, he spoke quietly to confirm his name before pleading not guilty to charges of murder and having an offensive weapon in public.
The not guilty pleas were met with an emotional outburst from a member of Harry’s family, for which she later apologised.
A trial of the boy, who cannot be named due to his age, has already been set for September 2.
Harry was with a group of friends near the viewing platform on Primrose Hill when he was stabbed at around 11.40pm on December 31.
Police officers provided first aid at the scene before paramedics arrived, but Harry’s life could not be saved.
The alleged killer, who was 16 at the time of the stabbing, was remanded back into custody by Mr Justice Cavanagh until the start of his trial.
