The olive oil industry generates a large amount of liquid waste known as olive mill wastewater (OMW). They are heavily loaded with organic matter and highly polluting polyphenols. Without prior treatment, these toxic effluents have a negative impact on the environment and human health. For decades, numerous scientific studies have been conducted to depollute these wastes, but this major problem has not yet been effectively addressed in practice. In this work, we propose an aerobic biotechnological treatment for OMW. The microorganism used is a marine mold native to shallow coastal waters of the marine ecosystem, where saline water is its natural habitat. Treating diluted OMW at a 1/5 ratio with the mycelium of this strain, which is isolated and purified, yielded interesting reductions in organic pollutants. Specifically, significant reductions of 68.08% in Chemical Oxygen Demand (COD), 69.35% in Biochemical Oxygen Demand (BOD5), and 78.99% in polyphenols were achieved. These results highlight the potential and practical viability of this process for real-world applications, especially due to the mold's ability to grow directly in liquid OMW despite its salinity.