The 2004 Indian Ocean tsunami, triggered by a megathrust earthquake along the Sunda Subduction Zone, highlighted the past vulnerability of coastal regions. Since then, ongoing investigations have focused on identifying potential tsunamigenic sources, particularly along the northern extension of the 2004 rupture zone, extending to the west coast of Myanmar. This paper examines future tsunami risks along Thailand’s Andaman coast. Tsunami modeling was conducted to assess the regional hazards from potential 7.8–9.4 earthquakes along this northern extension, which were identified from geological and geodetic assessments. The results indicate that an 9.0 earthquake near the Andaman Islands would have a significant impact on the Andaman coast, producing waves similar to the 2004 tsunami, with simulated wave heights reaching up to 26 m. Furthermore, GIS network analysis of pedestrian evacuation routes shows that 82% of signage-based routes are longer than the shortest paths, requiring evacuees to travel an average overlength of 528 m. These findings underscore the ongoing risk posed by large seismic events in this region. This study emphasizes the progress of preparedness and mitigation measures to address the future tsunami risk. By continuing to strengthen early warning systems, improve shelter availability, maintain evacuation signage, refine route planning, and promote public awareness, Thailand can enhance long-term tsunami resilience and provide greater preparedness and mitigation for coastal communities.