Effective management of coastal aquifers requires a thorough understanding of seawater intrusion (SWI). The Ghiss-Nekor aquifer is one such area where the extent of SWI is unclear. This study aimed to map the extent of SWI using the hydrogeochemical approach combined to geospatial techniques. Accordingly, we coupled various geochemical indicators, including four ionic ratios (Cl/HCO3, SO4/Cl, Na/Cl, and Mg/Mg+Ca) and two SWI indices (GQIswi and SMI), with geospatial methods to generate a map highlighting the regions most prone to SWI. As a result, approximately 20% of the study area was impacted by SWI, with 70% of SWI spots found within 2 km of the shoreline. A saline water detected up to 5 km from the coast was interpreted, through the use of the aquifer's stratigraphic model, as being caused by the intrusion of seawater from the Souani area that is trapped in a deep clay-marly substratum. These promising findings highlight the effectiveness of the applied hydrogeochemical approach and offer crucial information regarding the extent of SWI. This information will aid decision-makers in the Al Hoceima region in creating efficient groundwater management plans to tackle the effects of climate change, especially the shortage of water resources caused by declining levels of precipitation.