Algae play an increasingly vital role in the sustainable treatment of municipal wastewater, offering an eco-friendly alternative to conventional treatment methods. This chapter explores the utilization of algae in municipal waste treatment, focusing on their ability to remove nutrients, heavy metals, and contaminants from wastewater while producing valuable biomass. Algal-based systems leverage natural processes such as photosynthesis and nutrient assimilation to efficiently reduce nitrogen, phosphorus, and organic matter concentrations, thereby mitigating eutrophication risks. Additionally, algae can capture carbon dioxide and contribute to bioenergy production, further enhancing the environmental and economic benefits of their application. This chapter examines various algal treatment technologies, including high-rate algal ponds (HRAPs) and photobioreactors, discussing their design, operational parameters, and performance in municipal settings. Challenges related to scalability, climate adaptability, and integration with existing wastewater treatment infrastructure are addressed. Ultimately, the chapter highlights the potential of algae as a sustainable, low-energy solution for municipal waste treatment while contributing to the circular economy through resource recovery and bioenergy production.