The adult defendant and youth also face charges of grave and criminal assault, and possession of an offensive weapon.
Two other co-accused, who are both under-18, face charges of grave and criminal assault and affray.
All four individuals appeared in the Magistrate’s Court on Thursday and were remanded on conditional bail until 14 October, when they will appear in the Royal Court.
The charges relate to the stabbing of an 18-year-old in the Le Geyt Flats area on 9 January this year.