Historically, heatwaves are Australia's most destructive natural hazard in terms of loss of life. This study analyses statistics of fatalities associated with heatwaves in Australia from 2001 to 2018 as noted by a Coroner. At least 473 heat-related deaths were reported to a Coroner during the period of research, of which 354 occurred during heatwave conditions and, of these, 244 within buildings. Most indoor heatwave fatalities occurred in older housing stock. There was no overall trend in the number or rate of fatalities but, rather, a record of generally low numbers with periodic excursions into very high numbers. Almost two-thirds (63%) of heatwave fatalities occurred during two severe heatwave years: 2009 and 2014. The record was dominated by male fatalities. The risk of dying in a heatwave increased with age, socio-economic disadvantage, social isolation, geographical remoteness, the presence of disabilities (physical or mental) and some prescribed medications and the absence or non-use of air conditioning or other building heat protection. Other risk factors and behaviours were examined and recommendations to decrease future heatwave deaths suggested.