Microplastics (MPs) are widespread in aquatic environments due to their persistence, toxicity, and bioaccumulation. Detected in oceans, rivers, sediments, and even potable water, MPs threaten ecosystem food and human health. As global plastic production exceeds 367 million tons annually—only ~15% of which is recycled due to mishandling and poor waste infrastructure—a large fraction enters natural waterbodies, worsening the environmental crisis. In response, microalgae have attracted increasing scientific interest as a sustainable and biologically driven solution for MP remediation. Owing to their high adaptability and biomass productivity, microalgae offer a promising avenue for MP bioremediation via surface biosorption, entrapment by extracellular polymeric substances, enzymatic degradation, and bioflocculation—collectively providing an eco-friendly additional approach alongside the mainstreaming treatment processes. Despite this growing interest, the present literature still lacks an intuitive comprehension of the mechanisms underpinning the interactions between microalgae as well as the factors affecting these processes. This chapter fills that gap by providing a comprehensive overview of the mechanisms involved in MP remediation, evaluating the benefits and limitations of these approaches. Finally, it outlines future research directions with strategic insights for developing effective, scalable solutions to mitigate MP pollution.