Anomalously warm ocean temperatures have implications for many marine systems and industries, including mass coral bleaching and mortality, reduced aquaculture yields and altered wild fish migration patterns. Seasonal forecasts from dynamical ocean-atmosphere models of marine heatwaves and their drivers can be very useful tools for managers and business owners, allowing for proactive management responses. The Australian Bureau of Meteorology’s seasonal forecast model ACCESS-S1 currently produces operational real-time global forecasts of sea surface temperatures, with tailored outlooks produced for coral reef, aquaculture and wild fisheries management in Australian and New Zealand waters. Thermal stress forecast products have been developed, incorporating both the magnitude and duration of heat stress events, with widespread management applications. Advance warning of marine heat events can enable managers and industries to plan ahead and effectively manage resources to reduce impacts of such events. Seasonal forecasts are a valuable tool to improve both the understanding and the management of these events, as well as the complex interactions that lead to them, particularly in a changing climate.