Accidental petroleum discharges pose considerable hazards to marine biomes and coastal economies, particularly in vulnerable and heavily-trafficked maritime corridors such as Morocco’s northern Atlantic coastline. This investigation utilizes the OpenOil module within the OpenDrift framework to quantitatively simulate the dispersion and degradation of a theoretical 100-ton oil discharge in proximity to Asilah over a seven-day interval. The simulation incorporates real-time meteorological and oceanographic information from NOAA-GFS and CMEMS, encapsulating essential physical and biochemical phenomena including advection, diffusion, evaporation, emulsification, and biodegradation. The outcomes elucidate a predominant northeastward movement of the slick, with approximately 68% of the oil mass either dispersed in the aquatic column (37%) or subjected to evaporation and biodegradation (16% each). Approximately 3421 out of 5000 particles were beached along the Asilah–Tangier shoreline, emphasizing high-risk ecological areas such as estuaries, rocky coastlines, and fishing zones. Lagrangian dispersion coefficients were computed to evaluate horizontal spreading dynamics, while droplet size distributions corroborated the impact of wave activity and oil characteristics on emulsification behavior. These results accentuate the pivotal function of numerical modeling in oil spill prediction, emergency preparedness, and ecological risk alleviation. The study represents the inaugural high-resolution application of OpenOil to Moroccan waters, providing actionable insights for national oil spill response frameworks and reinforcing the significance of incorporating real-time simulation instruments into coastal monitoring systems.