Background Conflict among siblings is linked with potentially lifelong social, cognitive, and behavioural problems. Parents of siblings play a crucial role in the development of both the positive and negative relationships of their children. Despite this, relatively few parenting programmes specifically address how to manage sibling relationships marked by elevated levels of conflict. Methods This article presents the rationale, protocol, and potential implications of a randomised controlled trial evaluating a tailored version of the Triple P‐Positive Parenting Program for managing sibling conflict. This body of research seeks to illustrate how an evidence‐based parenting intervention can be successfully deployed to reduce rates of sibling conflict while improving children's social, emotional, and behavioural problems and enhancing parent competence and confidence. Conclusions Although sibling conflict is among the most widely reported and frequently cited concerns for parents, this is the first time a Triple P intervention has been used to target sibling conflict directly. If the intervention is found to be effective, it is hypothesised that the availability of an evidence‐based parenting programme focusing on sibling conflict will be highly appealing to parents and help engender a further destigmatisation of the notion of parents seeking parenting support.