Hazard Note 20 documents the analysis of the circumstances surrounding fatalities due to flooding in Australia from 1900 to 2015. The investigation includes exploring the socio-demographic and environmental factors surrounding the deaths. Overall there have been 1,859 fatalities within the 115 years, with distinct trends in relation to gender, age, activity and reason. The most deaths have occurred in Queensland and New South Wales. The majority of fatalities are male (79%) with children and young adults (<29) making up the greatest proportion of the fatalities.