The inability to effectively manage waste has evolved into one of the most significant challenges faced in oil palm plantations, and this failure has had an impact on the operations within the plantation. This study examines how attitudes (ATT), subjective norms (SN), and perceived behavioural control (PBC) affect both behavioural intention (BI) and sustainable waste management behaviour (SWMB) in the palm oil mills of Sabah, Malaysia. The theory of planned behaviour (TPB) serves as the primary theory in this research, which uses a conceptual framework. Distributed questionnaires to the top management of 133 oil palm mills were used to gather the data, and then they were processed using Smart-PLS V4. This research found out that SN and PBC have an influence on individuals’ BI and SWMB adaptations in Sabah’s oil palm mills. The SN was shown to have the strongest association between the SWMB and BI. However, attitudes resulted in no impact on either the intention to engage in sustainable waste management behaviour or on the actions themselves. Ultimately, the findings of this study will give a framework for the governance of palm oil waste in Malaysia by contributing to the development of a legislative and regulatory framework in this area that is more effective.