The incident was not seen by the referee, however Press Association Sport understands the FA was moved to take action after video replays showed the 29-year-old elbowing an Oldham player in the face off the ball
The ban is one of the longest in English football history and was handed down following an Independent Regulatory Commission hearing on Friday
"Calvin Andrew has been given a 12-match ban with immediate effect following an incident which was not seen by the match officials but caught on video," an FA statement read
"The player was involved in an act of violent conduct in or around the 77th minute of the game against Oldham Athletic on 29 October 2016.
"Furthermore, it was alleged that the standard punishment of three matches that would otherwise apply would be clearly insufficient.
"The player admitted his behaviour constituted violent conduct but denied the clearly insufficient element of the charge."
Rochdale have the right to appeal the ban, which will rule Andrew out until early in the new year.
Source : PA