- Missing since: Tuesday, January 7, 2003
- Last seen: Port Germein SA
- Jurisdiction: SA
- Year of birth: 1961
- Age now: 56
- Gender: Male
- Hair: Brown, Long
- Eyes: Brown
Gregory Christiansen disappeared on 7 January 2003 after telling the manager of a local hostel in Port Germein, South Australia that he was going for a walk.
He had arrived from Adelaide the day before by bus. His property was left in his hostel room.
If you have information that may assist police to locate Gregory please call Crime Stoppers on 1800 333 000.