The development of legislation aimed at reducing the incidence of firearm-related death is an ongoing interest within the spheres of criminology, public policy, and criminal justice. Although a body of research has examined the impacts of significant epochs of regulatory reform upon firearm-related suicides and homicides in countries like Australia, where strict nationwide firearms regulations were introduced in 1996, relatively little research has considered the occurrence of a specific type of homicide: mass shooting events. The current paper examines the incidence of mass shootings in Australia and New Zealand (a country that is socioeconomically similar to Australia, but with a different approach to firearms regulation) over a 30 year period. It does not find support for the hypothesis that Australia’s prohibition of certain types of firearms has prevented mass shootings, with New Zealand not experiencing a mass shooting since 1997 despite the availability in that country of firearms banned in Australia. These findings are discussed in the context of social and economic trends.