It happened at a house in the Fairways estate at around 4:30am this morning.
He sustained a number of stab wounds and was taken to St Luke's Hospital.
Another male teenager was arrested at the scene in connection with the assault, and investigations are ongoing.
Local Shock As Couple Found Dead At Their Bray Home
Gardaí are treating the case as a tragedy, and await post mortem results.
EirGrid Seeks Views On New Substations For North Wicklow
The North Wicklow Reinforcement Project will reinforce the electricity grid in North Wicklow, ensuring sufficient capacity is available for future increased demand.
Wicklow Receives 363 Applications For Vacant Property Refurbishment Grant
Over 120 previously vacant and derelict properties have been restored to residential use across Wicklow through the Vacant Property Refurbishment Grant
Storm Austen Warning for Wicklow With Heavy Rain Bringing Flood Risk
Difficult driving and localised flooding are possible from 7pm Thursday, with more wet and windy weather lined up for the bank holiday weekend.
Man In His 60s Dies After Truck And Car Collide On N81
8:00pm - 10:00pm
Love Songs on the Coast
Light rain
High: 13°C | Low: 7°C
Light rain
High: 13°C | Low: 7°C
Light rain
High: 12°C | Low: 6°C
Sunny intervals
High: 12°C | Low: 5°C
Light rain
High: 13°C | Low: 6°C