Antje Bornhak is a German mountain bike orienteer. At the 2002 World MTB Orienteering Championships in Fontainebleau she won a bronze medal in the long distance, and a bronze medal in the sprint. At the 2004 World MTB Orienteering Championships in Ballarat she won a bronze medal in the long course. At the 2005 World Championships in Banska Bystrica she won a gold medal in the relay, together with Anke Dannowski and Gerit Pfuhl, and a silver medal in the long distance.