This study focuses on how Indonesia's One Map Policy renders illegal palm oil plantations in Indonesia visible and the governance dilemmas this creates. Using Central Kalimantan as a case study, we first draw on spatial data to visualise the extent of illegal palm oil plantations on forest land. The vast majority of illegal palm oil is large plantations, with illegal independent smallholdings constituting just 0.4%. We then draw on key stakeholder interviews to analyse the governance dilemmas such visualisations create. We explore stakeholder perspectives of the new Omnibus Law and other attempts to legalise illegality. Four governance scenarios that emphasise the interests of either business, smallholders, environments, or adopt a multi-stakeholder perspective are developed and measured according to their different social and ecological land use implications. In the interests of promoting sustainable and effective governance for forests, peatlands and palm oil production, we caution against the pro-business option currently favoured by the Indonesian government that aims to legalise illegal plantations and which risks the reassignment of forests for commercial production. Our article outlines alternative policy solutions, including an approach that seeks to balance business and environmental interests while also paying heed to sustainable development needs. This approach could be applied in other contexts similarly struggling with the governance dilemmas about what to do when widespread land use illegalities are made visible.