The marine environment is increasingly threatened by chemical pollutants that pose serious risks to aquatic ecosystems, biodiversity and human health. This paper examines the sources, impacts and challenges posed by different classes of chemical pollutants in marine ecosystems, focussing on pollution from nutrients, pharmaceuticals, personal care products, pesticides, oil spills, endocrine disrupting chemicals and heavy metals. Pollution from nutrients, especially agricultural runoff, leads to eutrophication and harmful algal blooms that destabilise aquatic life. Pharmaceuticals and personal care products, often discharged from wastewater treatment plants, have shown the potential for bioaccumulation and chronic toxicity in marine life. Pesticides contribute to the degradation of coastal ecosystems, while oil spills damage marine habitats and species. Endocrine disrupting chemicals, including hormone mimics, disrupt the reproductive systems of aquatic organisms, and heavy metals, such as mercury, lead to neurotoxicity and bioaccumulation in the food chain. This paper highlights the complex interactions of these pollutants, their impact on the environment and the challenges of monitoring and mitigating their presence in marine ecosystems. Solutions require integrated global policies, advanced pollution monitoring technologies and sustainable practises to protect marine biodiversity and maintain public health.