The Makran Subduction Zone (MSZ) gained wide interest following the 1945 tsunamigenic earthquake. This three-part (A, B, and C) review provides a comprehensive and multidisciplinary synthesis of 80 years of research on tsunamigenic earthquakes associated with the MSZ. Part A (this paper) focuses on the fundamental tectonic and geophysical characteristics of the MSZ, including plate convergence, slab geometry, rupture segmentation, deformation patterns, active fault structures, and submarine morphology. Emphasis is placed on emerging insights into earthquake rupture mechanisms and their implications for tsunami generation. Subsequent parts address complementary aspects of the historical tsunamis (Part B), and the associated hazard and risk (Part C). Given the rapid increase of coastal population, critical infrastructure, and offshore development along the Arabian Sea, consolidating and critically synthesizing existing knowledge of the MSZ is essential. This review aims to provide a coherent scientific framework that supports improved seismic and tsunami hazard assessment, risk mitigation strategies, and improving tsunami hazard assessment, risk mitigation strategies, and regional coastal resilience planning for vulnerable coastal communities.