Global reviews of Marine Spatial Planning (MSP) show that Indigenous peoples’ involvement in MSP is low. When included, they are considered equal stakeholders, which conflicts with their understanding of custodianship. Indigenous knowledge is often integrated in a transactional way, lacking meaningful engagement with Indigenous ontological frameworks. This results in a misleading sense of inclusivity and misrepresentation of complex Indigenous knowledge and values. It is essential to decolonise this approach and challenge the data hegemony held by colonial sources. The data used for spatial prioritisation significantly influences management zonation. For Indigenous peoples to engage meaningfully in MSP, data must reflect their knowledge, laws, and values. We describe a collaboration led by Yanyuwa Sea Country custodians, alongside anthropologists, ecologists, and local knowledge holders. Through literature reviews, consultations, and publicly available data, we developed two value frameworks: one reflecting government and industry perspectives and the other based on a Yanyuwa-led ontology of value and threat related to their Sea Country. These frameworks inform a spatial cumulative risk assessment, exploring the challenges of incorporating Indigenous knowledge into MSP and supporting its decolonisation in Yanyuwa Sea Country.