Food security has become one of the major issues of our time. Many studies have highlighted issues and opportunities for enhancing food security. Yet, Indigenous food security has rarely been studied. There is no robust evidence and analysis to show how and why food security in Indigenous communities can be understood and is increasing or decreasing in the changing climate. This thesis investigates the political ecology of food security in the Indigenous communities of Sabah, Malaysia by unfolding the issues of access, knowledge, and power in Indigenous communities. By analysing two Indigenous communities in Malaysia’s Sabah, this thesis demonstrates that food accessibility for Indigenous people in the era of neoliberalism is largely determined by their ability to pursue a sustained contestation of the neoliberal narratives for state restructuring, leading to the changes in market-oriented and profit-driven agricultural policy and practice of food security. This process that has a limited or no recognition of the Indigenous knowledge, community, and culture, has rapidly changed the Indigenous food systems and traditional way of life. Indigenous food security is now seriously threatened. In Malaysia, the neoliberal agricultural policies based on market-driven agriculture and profit-oriented goals go hand in hand with the economic privileging of ‘modern’ usages of land and forest resources for oil palm plantations and timber production. These practices have undermined the Indigenous practices, knowledge, rights and innovations. For the indigenous Sabahan, their status as Bumiputra has been an essential strategy for them to legitimate their rights to practise traditional use of land resources. However, the status of indigeneity is not primordial, but it exists in relation to internally dominant Indigenous identities in Malaysia. The politicisation of indigeneity in Sabah is commonly triggered by some ‘federal factor’ of bureaucratised Bumiputraism and Islamisation. As a result, the Indigenous people, especially ...