Neelander Neel Sirohi, 31, had earlier pleaded not guilty to the rape charges at an Australian magistrate's court but today changed his plea to guilty before the Australian Capital Territory Supreme Court.
Sirohi picked up the woman, who was returning from a night out, at 3.20 am from a taxi stand near the Civic bus interchange in August 2013, the Canberra Times reported.
The woman had told police that she had little memory of the ordeal as she was heavily intoxicated, having consumed alcohol and prescription medication, and was feeling sleepy during the drive.
On returning home, the woman complaint to her mother and she was later medically examined, police alleged in court documents.
Justice John Burns today ordered a pre-sentence report be completed, and Sirohi will be brought back to court in August.