Abstract <p>Salinization of coastal aquifers poses a significant global environmental challenge, intensified by the overexploitation of groundwater and the rise in sea levels driven by climate change. Assessing the vulnerability of coastal aquifers to seawater intrusion is, therefore, crucial for the management of water resources in coastal regions. This study aims to assess the vulnerability of the Dradère-Souière coastal aquifer in Northern Morocco using the GALDIT-SUSI method. The findings indicate that 37.17% of the study area exhibits low vulnerability, 59.43% shows moderate vulnerability, and high vulnerability is confined to the vicinity of the Merja Zerka lagoon’s mouth, covering 3.40% of the area. To enhance the accuracy and relevance of the results, the weights were adjusted based on sensitivity analysis outcomes. Nevertheless, validating the GALDIT-SUSI method’s results and accurately characterizing seawater intrusion necessitates a multidisciplinary approach, encompassing hydrogeological studies, hydrochemical analyses, and geophysical investigations. To further refine the GALDIT-SUSI method, it is advisable to integrate it with other methodologies for assessing the vulnerability of water resources to diverse pollution sources.</p>