The 17-year-old, who cannot be named due to his age, pleaded guilty to the speeding offence in the Youth Court on Tuesday 21 May.
He was caught speeding in St Ouen on an evening in March.
Advocate James Bell, defending, said the speeding had been a one-off mistake.
Delivering the sentence, Magistrate Bridget Shaw said she hoped the teen had learnt a lesson by coming to court.
She said: “When you become a driver and are in charge of a motor vehicle. This is a lethal weapon.
“You decided to misuse that in a way that could have cost somebody else their life or cost you your life.
The Magistrate added that with only a few weeks’ experience, the boy was “one of the most inexperienced drivers on the road”.
The teenager was disqualified from driving for nine months and will have to sit a retest before he can drive independently again.