Abstract Background International concern regarding the increase in preventable harms attributed to adolescent alcohol consumption has led to growing political and medical consensus that adolescents should avoid drinking for as long as possible. For this recommendation to be adopted, parents and guardians of adolescents require information about strategies that they can employ to prevent or reduce their adolescent's alcohol use that are supported by evidence. Methods The Delphi method was used to obtain expert consensus on parenting strategies effective in preventing and reducing adolescent alcohol consumption. A literature search identified 457 recommendations for parents to reduce their adolescent child's alcohol use. These recommendations were presented to a panel of 38 Australian experts who were asked to rate their importance over three survey rounds. Results There were 289 parenting strategies that were endorsed as important or essential in reducing adolescent alcohol use by ≥90% of the panel. These strategies were categorised into 11 sub-headings: things parents should know about adolescent alcohol use, delaying adolescent's introduction to alcohol, modelling responsible drinking and attitudes towards alcohol, talking to adolescents about alcohol, establishing family rules, monitoring adolescents when unsupervised, preparing adolescents for peer pressure, unsupervised adolescent drinking, what to do when an adolescent has been drinking without parental permission, hosting adolescent parties, and establishing and maintaining a good parent-child relationship. The endorsed strategies were written into a document suitable for parents. Conclusions A comprehensive set of parenting strategies for preventing or reducing adolescent alcohol consumption were identified. These strategies can be promoted to parents to help them implement national recommendations for use of alcohol by young people.