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.
Wicklow Receives €10.72 Million to Repair Roads Damaged by Storm Chandra
Wicklow Apprentice Wins ESB HGV Mechanic Apprentice of the Year
A wheely good result for Daniel Diamond from Glenealy!
Wicklow Takes Two Spots In Top Five As Ireland's Best Music Festivals Are Revealed
Beyond the Pale and Kaleidoscope wow the crowds with festival fever flair finishing top five in nationwide research
Short-Term Extension Of Fuel Excise Cuts For Wicklow Families And Businesses
Tanaiste says extending measures is to offset 'cliff-edge' fall for people and businesses while monitoring inflation
Outdoor Swimming in Co. Wicklow To Become More Accessible
Funding of €25,000 has been secured to support accessible upgrades at Bray and Brittas Bay.
Sunny intervals
High: 21°C | Low: 12°C
Sunny intervals
High: 20°C | Low: 12°C
Sunny intervals
High: 22°C | Low: 10°C
Medium-level cloud
High: 21°C | Low: 10°C
Sunny intervals
High: 22°C | Low: 10°C
