Literature on global international student mobility (ISM) highlights the uneven nature of student flows--from the developing to the developed world--however, studies have yet to address whether this pattern is replicated within expanding regional networks. Utilizing social network analysis, UNESCO ISM data, and World Bank income classifications, this paper examines economic inequality in ISM from 2008-2012 globally and within the Southern African Development Community, the European Higher Education Area, the Union of South American Nations, and University Mobility in Asia and the Pacific. Findings reaffirm previous global analyses which indicate that higher-income countries play a preeminent role as receivers; whereas, lower-income countries function primarily as source nations. This study demonstrates that this pattern is replicated fractally within the four regional networks as well. Globally and regionally, economically developed countries comprise the core of the world-system in tertiary education while less-developed nations are relegated to peripheral status.