This chapter analyses the evolution of the metropolisation processes of Phnom Penh, the capital city of Cambodia. From the beginning of the 1990s, Phnom Penh's development has depended strongly on Western development and technical aid. However, since the 2010s, urban development processes have changed drastically due to the action of foreign developers, the transfer of new urban models, the fast development of secondary cities, the intensification of inter-urban connectivity at the national level, the consolidation of urban corridors, the rise of China as a key economic partner, and a change in the scale of urban development at the national level. The chapter thus argues that Phnom Penh has entered a new phase of development—so-called ‘post-dependency metropolisation’. This new phase is defined as a paradigm shift of urban development, whose foundations were built in a situation of economic and institutional dependency but which gradually evolved into a more complex system of resources exploitation, capital formation and circulation, and multilateral politico-economic cooperation at both regional and international levels. This post-dependency metropolisation has only recently begun to take shape, and its outcome remains uncertain.