<p>Ethiopia is widely recognized as highly vulnerable to climate extremes, primarily because its agriculture-based economy is highly sensitive to climate variability and precipitation changes. Household livelihood vulnerability, however, varies across different agroecological zones (AEZs). Despite this, empirical research examining how vulnerability to extreme climate events differs by AEZ remains limited. This study addresses this gap by providing AEZ-specific evidence on the livelihood vulnerability of smallholder farmers in the Sidama Region, Ethiopia. A total of 377 farmers were selected from three AEZs using simple random sampling. Qualitative data from focus group discussions, key informant interviews, and field observations complemented the quantitative analysis. The Livelihood Vulnerability Index (LVI) and the LVI–IPCC framework was applied to assess vulnerability through three key dimensions: exposure, sensitivity and adaptive capacity. Findings reveal notable disparities in vulnerability components across AEZs. The lowland AEZ showed the highest exposure (0.24), largely due to more frequent extreme climate variability and natural disasters. Sensitivity was also highest in the lowland (0.32), reflecting unsustainable land use, greater agricultural dependence and food insecurity. In contrast, adaptive capacity was relatively similar across AEZs, with index values of 0.16 in the highland, 0.15 in the midland and 0.14 in the lowland. The overall LVI was highest in the lowland (0.23), followed by the midland (0.22) and the highland (0.21), indicating a gradient of increasing vulnerability with declining altitude. Similarly, the LVI–IPCC index confirmed greater vulnerability in the lowland (0.03) compared to the midland (0.02) and the highland (0.01). The findings underscore the urgent need for AEZ-specific adaptation strategies to strengthen resilience and reduce livelihood vulnerability among smallholder farmers in the Sidama Region.</p>