Startup financing is a fundamental prerequisite for the survival, growth, and scalability of startups. Nevertheless, financing mechanisms in regional and peripheral innovation ecosystems, particularly in developing economies, remain insufficiently examined in a systematic manner. This study aimed to identify and prioritize the factors influencing startup financing in the regional innovation ecosystem of Bushehr Province using an exploratory sequential mixed-methods design. In the qualitative phase, data were collected through 14 in-depth semi-structured interviews with key actors in the Bushehr innovation ecosystem and analyzed using thematic analysis, resulting in the identification of five principal categories. Subsequently, the relative importance of the identified factors was evaluated and prioritized using the Fuzzy Analytic Hierarchy Process (FAHP). The findings indicate that stringent collateral requirements and the risk-averse behavior of financial institutions, together with limited financial resources and the absence of active regional venture capital investors, constitute the most significant barriers to startup financing. In contrast, limited awareness of innovation and reliance on personal financial resources are largely consequences of institutional and structural constraints. The results further reveal that financing challenges in peripheral innovation ecosystems are driven more by institutional constraints, financial infrastructure, and risk management mechanisms than by startups' internal characteristics.