BackgroundPoor housing conditions have been associated with increased mortality. Our main objective is to investigate association between housing inequality and increased mortality and to estimate the number of deaths that could be prevented if the population of Belgium faced the mortality rates of the least deprived housing deprivation decile.MethodsWe utilized individual-level mortality data extracted from the National Register in Belgium and relative to deaths that occurred between Jan 1, 1991 and Dec 31, 2020. Spatial and time-specific housing deprivation indices (1991, 2001, and 2011) were created at the level of the smallest geographical unit in Belgium, assigning these units into deciles from the most to least deprived. We calculated mortality attributable to housing inequality as the difference between the observed and expected deaths by applying mortality of the least deprived decile to other deciles. We also used standard life table calculations to estimate the potential years of life lost due housing inequality. Results18.5% (95% CI 17.7-19.3) of all deaths between 1991 and 2020 were attributable to housing inequality, corresponding to 584,875 deaths. Over time, life expectancy at birth increased for the most and least deprived deciles by about 3.5 years. The gap in life expectancy between the two deciles remained high, on average 4.6 years. Life expectancy in Belgium is reduced by approximately 3 years lost due to housing inequality. Conclusions Thousands of deaths in Belgium could be avoided if housing inequality was reduced. Hotspots of housing inequalities need to be localized and targeted with tailored public actions.