Manchester City brought in the 18-year-old from Fulham for a reported £12million last July, but he has made just three substitute appearances this season.
Patrick Roberts will now have the opportunity to gain more regular action at Celtic, who also took Jason Denayer – now at Galatasaray – on loan from City last season and signed Dedryck Boyata from them last June.
Celtic manager Ronny Deila had previously suggested he would only be open to making loan signings in this window if he could secure them for a longer period than six months, which he has been able to achieve with Roberts.
Outgoing City manager Manuel Pellegrini confirmed the move was imminent on Friday and insisted the Englishman remains part of the club’s long-term plans.
Meanwhile, City midfielder Bruno Zuculini has joined AEK Athens on loan until the end of the season.
By Taiwo Oyedeji
Twitter » Teeboy_88