Flexible photodetectors (FPDs) have been receiving increasing attention in recent years because of their potential applications in electronic eyes, bioinspired sensing, smart textiles, and wearable devices. Moreover, metal halide perovskites (MHPs) with outstanding optical and electrical properties, good mechanical flexibility, low‐cost and low‐temperature solution‐processed fabrication have become promising candidates as light harvesting materials in FPDs. Herein, we comprehensively review the developments of FPDs based on MHPs reported recently. This review firstly provides an introduction with respect to the performance parameters and device configurations of perovskite photodetectors, followed by the specific requirements of FPDs including substrate and electrode materials. Next, chemical compositions, structures and preparation methods of MHPs are presented. Then, the FPDs on the basis of single‐component perovskite and hybrid structure perovskite are discussed, subsequently, self‐powered flexible perovskite photodetectors were presented. In the end, conclusions and challenges are put forward in the field of FPDs based on perovskites. image