This dissertation focuses on the livelihoods and environments of small-scale commercial corn farmers in Chiapas, Mexico. I document processes of double exposure, dispossession, and farmer resistance using theories from agrarian studies, political ecology, and vulnerability studies. I draw on the double exposure schematic to examine corn farmers’ experiences of and responses to the dual challenges of neoliberalism and global environmental change. Grounded in an agrarian political ecology approach, this research provides nuanced evidence of how different factors of double exposure intersect and compound one another. Through in-depth, ethnographic work in corn-farming communities, I demonstrate how current challenges of double exposure are interconnected with historical and ongoing processes of dispossession and environmental degradation. I draw attention to several understudied dimensions of double exposure in the case of Mexican corn farmers, including: 1) the legacy of environmental degradation associated with Green Revolution modes of production and its implications for current vulnerabilities to ongoing environmental change; 2) the impact of the privatization and corporatization of Mexico’s seeds, inputs, and agricultural extension services; 3) the barriers to increasing the adaptive capacity and sustainability of farm systems within Mexico’s context of neoliberal food governance; and 4) the ways in which the crisis of double exposure can open possibilities for a double movement to emerge characterized by farmer-led, agro-ecological transformations.