The global ecosystem is experiencing swift degradation as a result of climate change propelled by human actions. This degradation has given rise to resource scarcity, a decline in biodiversity, and global warming. There is scientific consensus that climate change is anthropogenic (caused by humans) and that the power to mitigate it lies in human behaviour change. As the overseer of human resources in every organisation, the HRM function is facing mounting pressure to align its practices with environmental management in order to effectively address and reduce the organisation's carbon footprint. Consequently, this study aimed to investigate the influence of green employee rewards on employee pro-environmental behaviour in public universities in Kenya. The study developed a measurement model based on the Green Five Taxonomy to evaluate diverse employee green behaviours. It utilised multi-stage sampling, where the purposive sampling technique was used to select three public universities that embraced green HRM practices, followed by stratified random sampling to draw 123 participants from three strata: top management, middle-level management, and others (teaching and non-teaching). The research employed a correlational design, combining quantitative and qualitative methods, with data collected through online questionnaires. Results revealed a moderately strong, positive correlation between green employee rewards and employee pro-environmental behaviour (r =.545, p<.01), indicating a significant, positive link between the two. Additionally, ANOVA results showed that green employee rewards significantly and positively predict pro-environmental behaviour among employees (F (1, 88) = 37.126, p<.001). The study concluded that green employee rewards have a notable and positive influence on employee pro-environmental behaviour. However, it identified gaps in acknowledging and incentivizing environmental efforts among employees. Nonetheless, respondents still exhibited significant pro-environmental behaviour, even in the absence of explicit green rewards, an indication of employees' private green activism rooted in intrinsic motivation. The study made key recommendations among them: cash incentives, eco awards, eco-sponsorships, green recognition boards, and sustainable branded corporate gifts to nurture a sustainability culture.