["Natural Resources Forum, EarlyView. ", "\nABSTRACT\nFood security remains a critical global challenge, with Southern Africa facing particularly acute vulnerabilities due to complex interactions among agricultural, environmental, and socioeconomic factors. This study developed a comprehensive Composite Food Security Index incorporating 28 indicators across four key dimensions—availability, access, utilization, and stability—to systematically examine the multidimensional determinants of regional food security. Utilizing panel data from 10 Southern African countries (2000–2020), the study employed Two‐Stage Least Squares (2SLS) regression to address potential endogeneity and reverse causality biases, and an autoregressive integrated moving average with exogenous variables (ARIMAX) model to account for temporal dependencies and multicollinearity through Principal Component Analysis. This dual approach ensured robust causal identification while capturing dynamic relationships. The empirical findings revealed that agricultural factors—particularly increased government investment, enhanced fertilizer use, and land productivity—significantly enhance food security by improving productivity and system resilience. Conversely, environmental stressors, especially rising temperatures, pose substantial threats to food security through reduced crop yields and intensified water scarcity. Socioeconomic analysis demonstrated that high poverty and unemployment rates constitute major barriers to food access, while GDP per capita growth positively influences food security through enhanced purchasing power. The ARIMAX model revealed persistent autocorrelation, indicating that current challenges stem from deeply rooted historical patterns requiring sustained interventions. Policy recommendations emphasize integrated, multi‐sectoral approaches including climate‐resilient agriculture, increased agricultural investment, and targeted socioeconomic programs. The persistence of food security challenges, as demonstrated by the temporal analysis, highlights the necessity for long‐term, coordinated frameworks over short‐term interventions.\n"]