Youth alcohol consumption has been steadily declining in Australia, as in other countries; fewer young people are drinking and the age of initiation is increasing. However, young people, their parents and others in their communities continue to believe that adolescent (excessive) drinking is the norm. This perception, and the concurrent misperception that the majority of parents are happy to provide their underage children with alcohol, creates a perceived culture of acceptance of youth alcohol consumption. Young people believe that it is accepted, and even expected, that they will drink; and parents perceive that not providing their adolescent children with alcohol will lead to social exclusion. There is evidence that shifting social norms can have an immediate and lasting effect adolescents’ (and adults’) alcohol related attitudes and behaviors. This paper reports on a novel, community based social marketing intervention designed to correct misperceptions of alcohol related social norms in an Australian community. The project utilized a social marketing approach, informed by the full complement of Andreasen’s social marketing benchmarking criteria, and concurrently targeted adolescents, parents of adolescents and the broader community. Using extensive formative research and multiple evaluation techniques, the study demonstrates that shifts in community social norms are possible and suggests that this approach could be used more widely to support the positive trends in youth alcohol consumption and parental supply.