This review focuses on the photocatalytic degradation of dyes from textile wastewater, emphasizing the effectiveness and mechanisms of heterogeneous photocatalysis. The textile industry, particularly in countries like Pakistan, Sri Lanka, India, and China, generates significant amounts of wastewater containing various dyes, which pose environmental and health risks. Conventional methods for dye removal are often insufficient, leading to the need for advanced oxidation processes (AOPs), with photocatalysis being a promising technique. The review covers the classification of dyes, the fundamental techniques for dye degradation, and the general mechanism of photocatalysis, including direct and indirect mechanisms. It also discusses factors affecting photocatalytic dye degradation, such as pH, temperature, light intensity, catalyst concentration, dye concentration, electron acceptors, intermediate species, inorganic ions, and photocatalyst morphology. The review highlights the importance of photocatalyst regeneration and the applicability of photocatalytic technologies to real industrial wastewater. Finally, it provides an overview of the composition of photocatalysts, focusing on three generations of metal oxides, with detailed examples of their applications and limitations. The primary aim is to offer a comprehensive overview of photocatalytic degradation and explore its potential for future applications.This review focuses on the photocatalytic degradation of dyes from textile wastewater, emphasizing the effectiveness and mechanisms of heterogeneous photocatalysis. The textile industry, particularly in countries like Pakistan, Sri Lanka, India, and China, generates significant amounts of wastewater containing various dyes, which pose environmental and health risks. Conventional methods for dye removal are often insufficient, leading to the need for advanced oxidation processes (AOPs), with photocatalysis being a promising technique. The review covers the classification of dyes, the fundamental techniques for dye degradation, and the general mechanism of photocatalysis, including direct and indirect mechanisms. It also discusses factors affecting photocatalytic dye degradation, such as pH, temperature, light intensity, catalyst concentration, dye concentration, electron acceptors, intermediate species, inorganic ions, and photocatalyst morphology. The review highlights the importance of photocatalyst regeneration and the applicability of photocatalytic technologies to real industrial wastewater. Finally, it provides an overview of the composition of photocatalysts, focusing on three generations of metal oxides, with detailed examples of their applications and limitations. The primary aim is to offer a comprehensive overview of photocatalytic degradation and explore its potential for future applications.