Over the past decade,all-inorganic metal halide perovskites(MHPs,CsPbX3:X=Cl,Br,I) have been widely investigated as promising materials for optoelectronic devices such as solar cells and light-emitting diodes.MHPs are defecttolerant,which allows tuning of their bandgap without altering their photophysical properties.From a fundamental point of view,MHPs are excellent candidates for photocatalytic reactions due to their light-harvesting capability,high photogenerated charge-carrier mobility,long diffusion lengths,and tunable bandgap energy.In this review,we provide an overview of various MHP engineering strategies(e.g., surface,morphological,and structural modifications,heterojunction coupling,and encapsulation) which are directly linked to the charge-carrier mobility and lifetimes,and then to the photocatalytic efficiency.Specifically,we outline different synthetic approaches resulting in surface and morphological modifications,anion/cation substitution,metallic doping,coupling,and encapsulation that tremendously influence MHPs’ stability,optical properties,and charge-carrier dynamics at variable time scales(from fs to μs).We also provide an in-depth evaluation of the MHPs for variable photoredox reactions,discussing how the optical and electronic properties help to improve their stability and efficiency.