The conservation profession is increasingly seeking effective ways to reduce societal impact on biodiversity, including through targeted behaviour change interventions. Multiple conservation behaviour change programs exist, but there is also great uncertainty regarding which behaviours are most strategic to target. Behavioural prioritization is a tool that has been used effectively to support behaviour change decision‐making in other environmental disciplines and more recently for a small sub‐set of biodiversity behaviour change challenges. Here, we use behavioural prioritization to identify individual behaviours that could be modified to achieve biodiversity benefits in the state of Victoria, Australia. We use an adapted nominal group technique method to identify potential biodiversity behaviours and, for each behaviour, estimate the corresponding plasticity (or capacity for change) and positive impact on biodiversity outcomes. We elicited 27 behaviours that individuals could undertake to benefit or reduce their negative impact on biodiversity. This list was then used to prioritize 10 behaviours as determined by their likely effect(s) on biodiversity, plasticity, and current prevalence in Victoria. We take a first step in outlining a list of behaviours that can direct Victorian decision‐makers toward increasing positive and reducing negative impacts of society on biodiversity, guide motivated individuals to reduce their own biodiversity footprint, and more broadly, develop a behaviour change research agenda for behaviours most likely to benefit biodiversity.