The evidence is so strong, the experts said, that health watchdogs should overhaul guidelines for electronic device use by youngsters.
The team carried out an investigation among nearly 10,000 people aged 16 to 19 in Hordaland county, western Norway, in 2012, they reported in the journal BMJ Open on Tuesday.
The teens were questioned about their sleeping patterns, how long they looked at a screen outside of school hours and the type of gadget they used.
The respondents said they needed between eight and nine hours' sleep on average to feel rested.