The rainfed lowland areas in Northern Thailand develop drought during the rice-growing season. This study analyzes the Thai farmers’ vulnerability to socio-economic drought in Chiang Rai province in Northern Thailand. Socio-economic drought refers to a condition in which a decrease in precipitation affects the population's well-being and is linked to underlying vulnerability. This research was conducted in Phan District, Chiang Rai province, where the worst drought occurred in the area for more than a decade. An exploratory case study in the qualitative analysis was utilized to analyze the socio-economic vulnerability model by Blaikie et al. [6]. Data were collected from interviews with affected farmers (n = 50) and stakeholder engagement. The findings feature root causes, dynamic pressure, and unsafe living conditions explaining Thai farmers’ social vulnerability to drought. The root causes implicated in the rice system in Thailand are characterized by rainfed lowland where the water supply is unpredictable by too much and too little water in the same season. Dynamic pressure involved the government's policy-related drought management response, which was not adequately responsive to safety nets and social protection assessment in strategic plans and actions. Furthermore, rural Thai are less likely to migrate, particularly poor farmers and families with limited income, exposing them to unsafe conditions from consecutive droughts. As climate change impacts result in more extreme drought events, it is also crucial to understand the institutional context of governance responding to climate change mitigation and adaptation measures in broader livelihoods diversification strategies.