The 19-year-old, who was on loan at Bolton last season, will make the switch to Celtic Park subject to a medical.
Celtic said in a statement on their official club website: "Celtic Football Club can confirm that it has completed the signing of Saidy Janko from Manchester United on a four year contract, subject to receiving satisfactory medical results which should hopefully be with the Club tomorrow morning."
Janko was born in Zurich, Switzerland, and has represented his county at Under-19 level
He joined Manchester United from FC Zurich on summer transfer deadline day in 2013 before joining Bolton on loan this February
Source : PA
Source: PA