The 15-deck Princess Cruises vessel is set to dock in Fremantle on Sunday, December 18, after a 13-day coastal cruise.
Princess Cruises would not say how many people fell ill but confirmed: “passengers on Sun Princess had reported gastrointestinal symptoms confirmed as Norovirus during the current cruise”.
Side-effects of the highly-infectious virus include vomiting and diarrhoea.
A spokesperson said preventative health vigilance was already high on the ship after authorities warned that the Norovirus was active in the community.
“High sanitation levels were further increased and both the ship and terminal will be thoroughly cleansed,” the company said.