Green technology is gaining importance nowadays, it has become very important to synthesize various nanoparticles. This review mainly focuses on the phytosynthesis of silver nanoparticles (AgNPs) and shows their catalytic applications in the field of wastewater treatment. Plant-assisted synthesis of AgNPs has been documented by numerous studies. Plant-mediated synthesis has many advantages over conventional methods and is discussed comprehensively in this review. This critical review aims to help researchers to better understand and follow this rapid, cost-effective, and eco-friendly research area. Dye effluents in water bodies become a major environmental issue worldwide. This paper also offers a thorough understanding of the synthetic dyes such as Rhodamine B, Methylene Blue, Crystal violet, Methyl Orange, and Amido black 10B used in the textile industry, with a focus on the popular methods to degrade them from industrial wastewater, especially, chemical degradation, and photocatalytic dye degradation using silver nanoparticles and other Ag-systems. Additionally, the plausible mechanism involved in chemical and photocatalytic degradation was also provided. There are several review articles on all these topics, but such an in-depth study has not been investigated so far in the concerned research literature. [ABSTRACT FROM AUTHOR]