The study aimed to develop and validate a food literacy tool for Tanzanian adults. The Tanzanian nutrition, food, and health promotion experts evaluated the initial 23-question food literacy tool for its relevance to the context, where its content validity was determined. The construct validity involved the analysis of food literacy information collected in a cross-sectional study involving 709 adults (484 females and 225 males) sampled from rural and urban Tanzania. Exploratory Factor Analysis (EFA) was conducted to explore the underlying factor structure and identify the number of latent constructs. A confirmatory factor analysis (CFA) using structural equation modeling (SEM) verified the measurement model and confirmed the theoretical model’s validity and reliability. The descriptive statistics summarized the essential characteristics of the study sample. The final tool remained with 14 questions after removing questions with low factor loadings <0.5 and higher uniqueness above 0.60. The model achieved construct validity through convergent and discriminant validity and construct reliability through the composite reliability exceeding 0.60 and a Cronbach’s alpha value of 0.83 and above. The 14-question food literacy tool has been reviewed and evaluated by experts in food, nutrition, and public health; therefore, it is a valid measure of food literacy among adults in Tanzania. It is suitable for designing nutrition education programs and ensures accurate and reliable measurements for effective interventions and policy actions.