Discourses of “non-interference” have been central to Beijing’s stated “peaceful rise” and “win-win” approach to international diplomacy. This paper contests Beijing’s non-interference rhetoric through a case-study analysis of Cambodia. We have two core arguments: (1) interference by foreign powers is not limited to actions that challenge a regime’s leadership, but can also include the reinforcement of regimes that lack popular support, and; (2) Beijing’s “non-interference” rhetoric is not demonstrated in the context of Cambodia, where it has repeatedly interfered to reinforce Prime Minister Hun Sen’s leadership during times of political contestation. To make these arguments, the article offers a historical summary of Chinese interference in Cambodia followed by an analysis of the key domains in which Hun Sen’s regime supports Beijing’s geostrategic interests. These are support for Beijing’s One China Policy and its Belt and Road Initiative (BRI); support for Beijing in negotiations with ASEAN, and; Chinese economic interests. Collectively, we argue that these domains contribute to the advancement of China’s “core national interest”, and that it is for this reason that China has interfered in Cambodia’s domestic politics.