Assessment of the investment attractiveness of territorial units is a necessity for public administration bodies and individual investors. Public administration bodies assessing the investment attractiveness of territorial units can develop effective investment policies, while investors gain a solid information base for making informed investment decisions. In this context, creating a methodology for evaluating the investment attractiveness of individual regions is a critical challenge. This research addresses that challenge through detailed analysis and demonstrates the practical applicability of the proposed methodology using Armenia as a case study. The developed methodology is universal and, with some adaptation, can be applied to any country or territorial unit. The implementation of the developed methodology with software can provide the opportunity to obtain automatically generated data on the investment attractiveness of territorial units at any time.