Produced by the Population Health Analytics Laboratory in the Division of Epidemiology at the Dalla Lana School of Public Health, University of Toronto.Adult mortality rates in Ontario fell significantly between 1992 and 2015. Improvements took place in all regions of the province, and across several different types of mortality. This atlas offers strong, empirical evidence that Ontario’s health systems and policies have been increasingly successful at preventing death over time. However, mortality and its declines are not homogenous across the province. There are significant geographic, socioeconomic, and sex differences in mortality within Ontario’s population. Men, low socioeconomic status groups, and residents of southeast and northern Ontario experience the highest mortality rates. These groups are more likely to die, and to die prematurely, many from treatable or preventable causes, than the general Ontario population. Furthermore, socioeconomic and geographic groups with the highest mortality rates in 1992 also made the least improvements between 1992 and 2015. As a result, differences in mortality between LHINs and socioeconomic groups have grown larger since 1992.Supported by the Canadian Institutes for Health Research and the Canada Research Chairs Program