Climate variability has adversely affected the agricultural production of smallholder farmers in developing countries like Ethiopia. This study aims to examine the overall vulnerability of smallholder farmers to climate variability in different agro-ecological zones of Legambo district, north central, Ethiopia. The research used quantitative and qualitative data collection methods through cross-sectional survey data, focus group discussions, and key informant interviews from 347 randomly selected smallholder farmers. Then, 48 sub-component indicators categorized into twelve major components and then into three contributing factors of vulnerability (exposure, adaptive capacity, and sensitivity) were used to assess the livelihood vulnerability index (LVI) and LVI-based on the Inter-governmental Panel on Climate Change (IPCC) approach method in three agro-ecological-zones for vulnerability analysis. LVI and LVI-IPCC results showed that cold highland agro-ecology was the most vulnerable, and midland agro-ecology was the least vulnerable to climate variability effects. These findings can guide policymakers in designing adaptive strategies to enhance the resilience of smallholder farmers to climate variability.