When it comes to natural disasters, tsunamis stand out for their destructive nature, leaving their mark on landscapes and human history. The tsunami of 1755 BCE is a major historical event that struck the countries around the Gulf of Cadix, inflicting significant damage to infrastructure and resulting in substantial human casualties. This study investigates a coastal inundation deposit located in the fluvial plain of Oued Mlaleh (Tangier Bay, northern Morocco). The Holocene sequence is studied using a multiproxy approach, involving sedimentological, morphoscopic, and micropaleontological analyses. These analyses collectively provide strong evidence of a high-energy event.