This review discusses advancements in transparent conductive oxides (TCOs) for photoelectrochemical (PEC) applications. TCOs are crucial for PEC devices due to their transparency and conductivity, enabling efficient solar energy conversion. The review highlights that doping can enhance TCO conductivity while maintaining optical transmission, and further modifications like plasma treatment, hot isostatic pressing, and carbon nanotube (CNT) integration can improve TCO properties. TCOs such as ZnO, AZO, ITO, and FTO are discussed, with their properties, fabrication techniques, and challenges. The review emphasizes the need for advanced theories to understand structure-property relationships and the integration of multiple modification strategies to enhance TCO performance in PEC devices. Key findings include the importance of optimizing bandgap energy, improving conductivity, and enhancing stability for efficient PEC applications. The review also explores various fabrication methods like chemical vapor deposition (CVD), low-pressure CVD, and magnetron sputtering, along with modification techniques such as element doping, plasma treatment, and CNT integration, which are essential for improving TCO performance in PEC devices. The study concludes that further research should focus on enhancing transparency, conductivity, and stability of TCO materials for efficient PEC applications.This review discusses advancements in transparent conductive oxides (TCOs) for photoelectrochemical (PEC) applications. TCOs are crucial for PEC devices due to their transparency and conductivity, enabling efficient solar energy conversion. The review highlights that doping can enhance TCO conductivity while maintaining optical transmission, and further modifications like plasma treatment, hot isostatic pressing, and carbon nanotube (CNT) integration can improve TCO properties. TCOs such as ZnO, AZO, ITO, and FTO are discussed, with their properties, fabrication techniques, and challenges. The review emphasizes the need for advanced theories to understand structure-property relationships and the integration of multiple modification strategies to enhance TCO performance in PEC devices. Key findings include the importance of optimizing bandgap energy, improving conductivity, and enhancing stability for efficient PEC applications. The review also explores various fabrication methods like chemical vapor deposition (CVD), low-pressure CVD, and magnetron sputtering, along with modification techniques such as element doping, plasma treatment, and CNT integration, which are essential for improving TCO performance in PEC devices. The study concludes that further research should focus on enhancing transparency, conductivity, and stability of TCO materials for efficient PEC applications.