The woman has admitted cutting a tag off the dress and putting it in her handbag in 2014.
A shop assistant stopped her after an alarm rang as she left the shop and the $276 dress was spotted in her bag.
Police were called and the woman received a formal caution but was not prosecuted.
The psychologist later apologised to the shop and paid $257 for the dress as it had been destroyed by the removal of the tag.
The shop cannot be named due to suppressions, but the incident did not occur in a Karen Walker store.
A Psychologists Board committee charged her with professional misconduct over matters including failures to discuss with her employer the shoplifting caution and a drunk-driving conviction.
The tribunal found the psychologist guilty of professional misconduct and of doing something - the shoplifting incident - that was likely to bring discredit to her profession.