This study aims to analyze the impact of Foreign Direct Investment (FDI) on institutional quality and economic growth in Tunisia using statistical analysis via SPSS software. A purposive sample of 300 participants was selected, including investment officials, representatives of governmental bodies, economic experts, and academics. The study relied on primary data collected through surveys, in addition to secondary data from official sources such as the World Bank and the National Institute of Statistics in Tunisia. Various statistical tools were used, including frequency analysis, Pearson correlation test, and multiple regression analysis to examine the relationship between the variables. The results indicated a strong positive relationship between FDI and institutional quality in Tunisia, with a correlation coefficient of 0.72 (p < 0.01), indicating a significant positive effect. Furthermore, FDI was found to have a positive impact on economic growth, with the multiple regression analysis showing an effect size of 0.65 (p < 0.05). When institutional quality was included as an intermediary variable, the effect size increased to 0.79, reinforcing the role of institutional quality in enhancing the impact of FDI on economic growth in Tunisia.