The loan move will see the youngster given the immediate chance of winning trophies and playing regular football.
Since his big money move from Fulham, which could cost up to £12 million, the winger hasn’t had the first-team opportunities due to the prowess in City’s squad.
Instead he’s had to settle for appearances in the Capital One Cup and a four-minute cameo appearance against Tottenham last September.
The 18-year-old has made just three appearances for the Premier league club this season and wants to get regular first-team football in order to develop his overall game to help fight for a place in the Blues squad.
Celtic took John Guidetti and Jason Denayer on loan from City last season and the latter proved to be a big hit with fans and won the young player of the year.
But the move ultimately stunted Celtic’s progress, as they had to find another replacement over the summer for the Belgian defender.
Roberts currently represents England at Under-19 level and has 14 caps to his name, scoring six goals for his country.
Some feel the squad was already more than capable of winning a domestic treble, but the lack of ambition to qualify for the Champions League shown by this move has angered and worried Celtic fans.
However the 18-month move will ease some fears about becoming a ‘feeder’ club.