The 17-year-old, who is predominantly a central defender, has put pen to paper on a three-and-a-half year deal after a successful trial and will go into the club's development squad.
The Switzerland Under-19 international told the club's official website: "I am delighted to join Newcastle United.
"Today is a big day for me. I've always wanted to sign for a club in the Premier League and Newcastle is one of the biggest there is.
"I want to finish my development here with the reserves before one day training with the first team and hopefully breaking into the first team."
Newcastle United's FIVE January signings:-
Mathieu Debuchy,
Mapou Yanga-Mbiwa
Yoan Gouffran
Moussa Sissoko
Massadio Haidara
Kevin Mbabu
NEWCASTLE UNITED FC 2012/13
Newcastle United Fixtures
Saturday February 2 2013 15:00 v Chelsea (H)
Saturday February 9 2013 12:45 v Tottenham (A)
Thursday February 14 2013 v Metalist (H)
Thursday February 21 2013 v Metalist (A)
Saturday February 23 2013 15:00 v Southampton (H)