Concerns about potential transmission at the awards ceremony at the Opera House were raised after it was revealed a food and beverage worker who tested positive for the virus worked at the event while infectious.
However, while all attendees have been directed to monitor for symptoms, NSW Health does not consider them to be close or casual contacts.
"South Eastern Sydney Local Health District (SESLHD) has been notified of one case of COVID-19 in an employee who worked at the Sydney Opera House while infectious," a SESLHD spokesperson said.
"NSW Health has identified the venue as low risk and the SESLHD Public Health Unit is currently investigating this matter."
The employee does not have the Omicron variant of concern, and is currently in isolation.
All guests and workers were required to be vaccinated in order to attend, while AACTA has said the awards were a COVID-safe event.
NSW on Saturday recorded 560 new COVID-19 infections, the highest number since October 8. However, the number of hospitalisations decreased to 150, a drop of eight compared to the previous day.