Photochemical [2+2] cycloaddition reactions have been developed as a promising route to generate photoswitchable structures and a wide variety of frameworks. There are numerous examples of discrete molecules that undergo cycloaddition reactions. However, photocycloaddition in coordination polymers (CPs) with potential applications is relatively less explored. Hence, the synthesis of such novel photoreactive CPs for diverse applications is a challenging task. This Frontier article highlights recent advances in the solid-state [2+2] cycloaddition of CPs and its impact on their applications.