The study analyzed the factors influencing the profitability of onion marketing in Anambra State, Nigeria. This study employed a survey research design, using a structured questionnaire to collect primary data from 100 onion marketers in Awka South Local Government Anambra State, Nigeria. The sample was selected through multistage sampling techniques. Multiple regression analysis and 4-point likert scale were used to analyze the factors affecting onion marketing and constraints faced by the marketers. The findings revealed that age (coefficient = 0.125, p = 0.020), level of education (coefficient = 0.190, p = 0.000), and marketing experience (coefficient = 0.145, p = 0.001) positively affect onion marketing profits. Conversely, transportation costs (coefficient = -0.140, p = 0.002) and security challenges (coefficient = -0.095, p = 0.071) negatively impact profitability. The study identified key constraints, including high transportation costs (84%), lack of credit facilities (47%), and inadequate storage facilities. The research provided a comprehensive overview of the onion marketing sector, offering valuable insights for policymakers, financial institutions, and local stakeholders involved in the agricultural sector.