Globally, there is no single universally agreed-upon definition of Indigenous peoples (IPs), yet specific criteria are typically used to define whether someone is Indigenous or not, namely self-identification, historical continuity, linkage to ancestral land, and distinctive social, cultural, and economic systems. This paper argues that the definition criteria act as guiding principles to explain the situation of IPs rather than recognising IPs’ collective rights to their lands, which are critical for nature conservation. By drawing the insights from selected cases, we found that either one or two of these criteria, such as cultural and self-identification, are commonly applied to identify IPs. The cases also showed that recognising collective rights of IPs to land has been found to offer a positive outcome for nature conservation and associated socio-cultural and economic opportunities for the people (e.g. biodiversity conservation, greenhouse gas abatement). We emphasise that not only the definition, but the legal recognition of land rights and involvement of IPs would be of the utmost importance to continue cultural practices attached to their ancestral lands, allowing them to be involved with natural resource management and conservation decision-making, that eventually relates to self-determination, equity and social and economic justice.