It happened on the Glenshane Road in Londonderry during the early hours of this morning , Sunday 13 July.
The man was a pedestrian who was struck by a car close to the junction of the Drumahoe Road around 1:50am.
Police are appealing for anyone who witnessed a collision or anyone who was travelling on the Glenshane Road early this morning and who saw the young man.
He was wearing a grey hooded top and blue jeans walking along the footpath or road to contact the Collision Investigation Unit at Steeple Police Station on local Police at Strand Road on the non-emergency number 101.
The Glenshane Road remains closed between Church Brae and Millbrook Park at this time.