Government, research and nonprofit conservation organisations are increasingly working to encourage pro-biodiversity attitudes and behaviours, using behaviour change and public engagement approaches such as environmental education and media campaigns. Despite these efforts, there remains an intention-action gap, where even people who say they care about the environment still do not act for nature. We determined five broad categories of potential barriers preventing individuals from engaging with biodiversity conservation that are most relevant to conservation professionals working in public and stakeholder engagement. We provide examples of intervention and messaging strategies that may assist in overcoming these barriers. We recommend conservation professionals consider these barriers when planning engagement programs and behaviour interventions.