<p>The main objective of wastewater treatment (WWT) is to remove as many pollutants as possible from water. A traditional wastewater treatment system (WWTS) is unsuitable for treatment due to high energy requirements, emissions of greenhouse gases (GHG), and substantial sludge production. Using microalgae for the WWT could be a better option due to their ability to remove a variety of pollutants and produce valuable algal biomass. The studies show that microalgae can remove 60–95% N, 70–98% P, 65–90% COD, and BOD, use CO₂ for glucose production, and efficiently adsorb heavy metals ranging from 54 to 99% for their growth. In addition, microalgae reduce dye and pesticide concentrations by 60–98%, as well as concentrations of microorganisms and emerging contaminants (ECs) 40–95%. Additionally, the algal biomass produced during WWT is used for biofuel, biochar, and bio-fertilizer production. However, the creation of an algal-based treatment system requires a large area, continuous monitoring, and substantial capital investment, which makes industrial-scale upscaling difficult. This review examine recent studies, factors affecting microalgal performance, and the integration of diverse organisms and techniques with microalgae to improve treatment efficiency.</p>