Among the various effects of high-speed rail (HSR), a direct benefit to users has been measured as an increase in the gross domestic product (GDP) by the conventional cost–benefit analysis (CBA), which was institutionalized in the U.K. In recent years, the importance of capturing indirect benefits to non-users has also been broadly discussed. The indirect benefits of HSR can mainly be classified into two perspectives: regional economy and personal quality of life (QOL). In this study, we modeled the mutual enhancement between those effects and analyzed the indirect benefits of the Mumbai–Ahmedabad high-speed rail (MAHSR), which is currently under construction as the first HSR in India, an emerging country with a rapidly growing economy. The indirect benefit to the regional economy along the MAHSR corridor was estimated by industry and by zone. Additionally, the indirect benefit on personal QOL by individuals’ attributes and by zone through the mutual enhancement with the regional economy was also estimated. The personal QOL tends to show greater effects in the middle cities than those in the two metropolitan areas of Mumbai and Ahmedabad. This method can evaluate interregional disparity by identifying the differences in benefits by person, according to age, income, etc., which cannot be evaluated based on a mass measure, e.g., GDP, in the conventional CBA.