The IPCC has begun to acknowledge, albeit slowly, the importance of Indigenous knowledge (IK) systems in contributing to understandings of climate change and effective climate action. Yet Indigenous Peoples (IPs) and IK systems remain largely excluded and marginalised from the IPCC global assessment reports. IPCC scientists and leaders have a unique and specific obligation to IK systems that does not extend to other knowledge systems. IK is the knowledge of rights holders and therefore acknowledging and respecting the self-determination of IPs over their knowledge – including how it is used, interpreted, and synthesised – is imperative. There are examples of IPs organising themselves in other international spaces that could inform how the IPCC can approach a stronger, more durable engagement with IPs. Perhaps the ultimate challenge for the IPCC is that when bringing IK systems together with other knowledge systems, the framing of evidence must reflect the diversity of these distinct and discrete ways of knowing. Examples from the lived experience of the Inuit Circumpolar Council in engaging with the IPCC demonstrate diverse channels for engagement, yet significant limitations persist.