Ireland flyhalf Jackson, 25, pleaded not guilty, the first time he has formally responded to the charges since they were brought against him in July. They relate to an incident alleged to have occurred at a house in Belfast a year earlier.
Ulster teammate Stuart Olding, 24, faces two counts of rape over the same incident and is due before the same court on Friday for a trial date to be set. His lawyer has said Olding strongly denies the accusations.
Neither will play at club or national level until the court case is concluded, the Irish Rugby Football Union has said.
Jackson has played 25 tests for Ireland, mainly as an understudy to British and Irish Lions flyhalf Johnny Sexton. Olding has represented his country four times at centre.
(Reporting by Ian Graham, editing by Padraic Halpin, Larry King)
