A comprehensive review of the sensing utilities of cesium lead halide perovskites (CsPbX₃; X = Cl, Br, I) and their composites is presented. These materials exhibit exceptional optoelectronic properties, making them suitable for various sensing applications, including metal ion detection, anion detection, chemical sensing, bioanalysis, and environmental monitoring. The review highlights the structural stability and optoelectronic properties of CsPbX₃, which are crucial for sensor performance. The materials show high chemical stability at elevated temperatures and exhibit bright emission with high photoluminescence quantum yield (PLQY). The bandgap of CsPbX₃ can be tuned to achieve red-to-blue emission, and the material can exist in different crystal phases depending on temperature and halide ion size. The surface morphology and potential of CsPbX₃ can vary when interacting with different analytes, leading to distinct sensor responses. The review also discusses the synthesis methods, design requirements, advantages, and limitations of CsPbX₃ and their composites. The materials have been used in various sensing applications, including the detection of metal ions, anions, chemicals, explosives, bioanalyses, pesticides, fungicides, cellular imaging, volatile organic compounds (VOCs), toxic gases, humidity, temperature, radiation, and photodetection. The review emphasizes the importance of understanding the underlying mechanisms of sensing and the need for further research to improve the practical applications of these materials. The review also addresses the challenges in the stability of CsPbX₃ in aquatic environments and the need for further investigations into the mechanisms of anion exchange and detection. The review concludes that CsPbX₃ and their composites have significant potential for sensing applications, but further research is needed to optimize their performance and expand their practical applications.A comprehensive review of the sensing utilities of cesium lead halide perovskites (CsPbX₃; X = Cl, Br, I) and their composites is presented. These materials exhibit exceptional optoelectronic properties, making them suitable for various sensing applications, including metal ion detection, anion detection, chemical sensing, bioanalysis, and environmental monitoring. The review highlights the structural stability and optoelectronic properties of CsPbX₃, which are crucial for sensor performance. The materials show high chemical stability at elevated temperatures and exhibit bright emission with high photoluminescence quantum yield (PLQY). The bandgap of CsPbX₃ can be tuned to achieve red-to-blue emission, and the material can exist in different crystal phases depending on temperature and halide ion size. The surface morphology and potential of CsPbX₃ can vary when interacting with different analytes, leading to distinct sensor responses. The review also discusses the synthesis methods, design requirements, advantages, and limitations of CsPbX₃ and their composites. The materials have been used in various sensing applications, including the detection of metal ions, anions, chemicals, explosives, bioanalyses, pesticides, fungicides, cellular imaging, volatile organic compounds (VOCs), toxic gases, humidity, temperature, radiation, and photodetection. The review emphasizes the importance of understanding the underlying mechanisms of sensing and the need for further research to improve the practical applications of these materials. The review also addresses the challenges in the stability of CsPbX₃ in aquatic environments and the need for further investigations into the mechanisms of anion exchange and detection. The review concludes that CsPbX₃ and their composites have significant potential for sensing applications, but further research is needed to optimize their performance and expand their practical applications.