The conclusions come from analysis of different forms of the elements oxygen and strontium in his tooth enamel.
Analysis on a previous skeleton found near Stonehenge showed that that person was also a migrant to the area.
The findings will be discussed at a science symposium in London to mark the 175th anniversary of the British Geological Survey (BGS).
The “Boy with the Amber Necklace”, as he is known to archaeologists, was found in 2005, about 5km south-east of Stonehenge on Boscombe Down.
The remains of the teenager were discovered next to a Bronze Age burial mound, during roadworks for military housing.
“He’s around 14 or 15 years old and he’s buried with this beautiful necklace,” said Professor Jane Evans, head of archaeological science for the BGS.