The New Economic Geography (NEG) incorporates social space into neoclassical models, and claims to provide an explanation of uneven development within the parameters of economic orthodoxy. It is among the most influential recent innovations in mainstream economics – Paul Krugman was awarded the 2008 Nobel Prize in Economics for his contributions to the NEG, and it provided the theoretical inspiration for the World Bank's 2009 World Development Report. Drawing on the work of David Harvey and Henri Lefebvre, this article interprets the NEG as a colonising project in both its theoretical claims and its practical applications. Theoretically, the NEG colonises the disciplinary terrain of economic geography while replacing its substantive content with the abstractions of neoclassical economics. In practical terms, the NEG has been instrumental in the World Bank's ‘new spatial approach to development’, which aims to fully colonise peripheral regions of the global economy through constructing the spatial infrastructures necessary for globalised production and exchange. The social contradictions implicit in this project are revealed in the case of the Plan Puebla Panamá, a regional development programme for southern Mexico and Central America, based on the NEG, and identified by the World Bank as a prototype for its spatial approach to development. The article thus provides a critique of the NEG as a theoretical approach and as a policy tool, demonstrating the increasing significance of the production of space within the neoliberal project, and cautioning against the transformation of socio-spatial reality in the image of technocratic abstractions.