The agricultural sector is vital to Bangladesh’s economy, yet smallholder farmers, particularly in northern regions, remain among the most vulnerable to climate change impacts. This study assesses smallholder farmers’ vulnerability to climate change by examining their perceptions, experiences with meteorological hazards, and the factors contributing to their susceptibility. Primary data were collected through a cross-sectional survey of 400 smallholder farmers from two climate-sensitive districts in northern Bangladesh. A Socioeconomic Vulnerability Index (SeVI) was developed using 10 exposure, 15 sensitivity, and 13 adaptive capacity indicators to quantify vulnerability. The results show that most people who answered the question believe that climate change is real, and almost a third of them think that human activities are to blame. The SeVI analysis revealed that most smallholder farmers experience high exposure to climate-related hazards. Key determinants of vulnerability included income, education, access to infrastructure, credit facilities, and landholding size. The findings indicate that there is an urgent need for targeted educational, financial, and institutional interventions to strengthen adaptive capacity. This study provides valuable insights for policymakers and development practitioners aiming to enhance climate resilience among smallholder farmers in northern Bangladesh.