Planet Earth is undergoing unprecedented levels of environmental degradation and destruction at a global scale. Incentivizing people to adopt behaviors that are compatible with a sustainable future will help address the current ecological crisis. However, it is first necessary to understand the psychological drivers of pro-environmental behavior. Here, we examined whether greater levels of environmental knowledge and empathy predicted higher levels of pro-environmental behavior in an Australian population sample. We aimed to advance our understanding of the psychological variables that motivate people to act in pro-environmental ways, while also advancing the ongoing debate amongst conservation scientists regarding the relative importance of fostering empathy. Correlational analyses revealed that objective, verifiable knowledge was a strong predictor of pro-environmental attitudes and behavior. Empathy also correlated positively with pro-environmental attitudes and behavior, but with a dissociation with respect to its cognitive and affective components. Multivariate analyses revealed that knowledge was a stronger predictor of both pro-environmental attitudes and behavior after controlling for individual variation in cognitive and affective empathy. This finding casts doubt on the claim by compassionate conservationists that fostering empathy is the key to solving the current environmental conservation crisis. Future research should aim to extend the present findings by testing whether a more exhaustive test of participants’ environmental knowledge and other measures of empathy, including empathic competencies and the recently developed Emotional and Cognitive Scale of the Human–Nature Relationship (ECS-HNR), yield the same dominance of knowledge over empathy.