Abstract:  The history of foreign relations is considered one of the highly significant topics in the civilizational history of the Islamic world during the medieval period, as naval fleets played a prominent role in it; they were not just a military force, but also a tool that contributed to shaping commercial and diplomatic relations, especially in the Mediterranean basin. Therefore, in this research, we sought to highlight the role of the Moroccan naval fleet in trade and diplomatic relations during the medieval period, by posing the issue of emphasizing its contribution and effectiveness in trade exchange and diplomatic missions; the research demonstrated how these fleets played a crucial role in managing geopolitical balances, imposing maritime sovereignty, and facilitating trade exchanges across the sea and desert, as well as performing advanced diplomatic tasks, manifested in treaties, missions, and maritime negotiations, which enabled it to build strong relations with kingdoms such as Spain and Italy, through which it gained military and economic support that helped strengthen its stability and expand its influence in the Mediterranean Sea, significantly affecting maritime security in the region, which played a part in protecting Moroccan coasts from piracy and attacks.