Abstract Ferroelectric materials commonly serve as gate insulators in typical field‐effect transistors, where their polarization reversal enables effective modulation of the conductivity state of the channel material, thereby realizing non‐volatile memory. Currently, novel 2D ferroelectrics unlock new prospects in next‐generation electronics and neuromorphic computation. However, the advancement of these materials is impeded by limited selectivity and narrow memory windows. Here, new concepts of 2D ferroelectric perovskite/MoS 2 channel heterostructures field‐effect transistors are presented, in which 2D ferroelectric perovskite features customizable band structure, few‐layered ferroelectricity, and submillimeter‐size monolayer wafers. Further studies reveal that these devices exhibit unique charge polarity modulation (from n ‐ to p ‐type channel) and remarkable nonvolatile memory behavior, especially record‐wide hysteresis windows up to 177 V, which enables efficient imitation of biological synapses and achieves high recognition accuracy for electrocardiogram patterns. This result provides a device paradigm for future nonvolatile memory and artificial synaptic applications.