Climate change is impacting marine organisms and ecosystems through more frequent extreme weather events, such as Marine Heatwaves (MHWs) and increased precipitation, particularly along the south-eastern Australia coast, a climate change hotspot, and the centre of the Sydney rock oyster's distribution. This study aimed to determine the impact of MHWs and low salinity on the survival and growth of juvenile Sydney rock oysters, Saccostrea glomerata. Oysters were exposed to an abrupt and gradual temperature increase (26-36°C) and decreased salinity, and survival and growth were measured. Survival was greater when exposed to a gradual rather than abrupt temperature increase from 26-36°C, while growth was greater with abrupt temperature increase. Oysters exposed to a gradual increase in temperature also survived longer at higher temperatures (36°C) than those exposed to abrupt exposures. When the dual stressors of MHWs and reduced salinity were combined, there was greater mortality at low salinities (15 ppt & 10 ppt) and high temperatures (36°C) compared to higher salinities (25 ppt & 35 ppt). This suggests that Sydney rock oyster’s have capacity for acclimation to a gradual MHW, but survival will be impacted by more frequent MHWs and low salinity events, with combined stressors having a synergistic negative effect.