In March/April 2018 Canadian public health authorities investigated an outbreak of norovirus linked to consumption of raw oysters. As of April 27, 172 cases had been reported by 3 provinces: British Columbia (132), Alberta (15), and Ontario (25). No deaths had been reported. Individuals became sick between mid-March and mid-April 2018. Most individuals who became sick reported eating raw oysters from the south and central part of Baynes Sound, British Columbia before onset of symptoms. Stool collected from several case patients were laboratory confirmed with norovirus.