The shift to green ports is essential for meeting worldwide sustainability targets and lowering emissions related to maritime activities. This paper presents a comprehensive analysis of the Port of Bar in Montenegro and its prospects for transforming into a low-carbon sustainable port hub within the Adriatic region. By a mixed-method approach consisting of empirical data, theoretical modeling, expert interviews, and other relevant methodologies, the study designs a comprehensive roadmap for the port’s multi-phase green transition. The first phase (2026–2030) focuses on partial electrification of cargo handling equipment, installation of on-site photovoltaic systems, and modernization of the Port Community System (PCS) to improve efficiency and environmental monitoring. The second phase (2030–2038) includes full electrification of port operations, Onshore Power Supply (OPS) accessibility for vessels at berth, and full renewable resource adoption. Results indicate the measures can significantly reduce annual CO2 emissions during the first phase, with a long-term potential to attain net-zero emissions. This transformation is in line with international regulations, European Union policies, as well as Montenegro’s national strategies and policies, positioning the Port of Bar as a regional model for green port development.