Abstract Sodium niobate (NaNbO )‐based dielectrics have received much attention for energy storage applications due to their low‐cost, lightweight, and nontoxic nature. The field‐induced metastable ferroelectric phase in NaNbO ‐based dielectrics, however, leads to a large hysteresis of the polarization–electric field (P–E) loops and hence deteriorate the energy storage performance. In this study, the hysteresis was successfully reduced by introducing Bi and Ti into A‐site and B‐site of NaNbO , respectively. MnO addition was added to further increase the ceramic density and enhance the cycling reliability. As a result, a high recoverable energy density of 4.3 J/cm and a high energy efficiency of 90% were simultaneously achieved in the ceramic capacitor at an applied electric field of 360 kV/cm. Of particular importance is that the ceramic capacitor exhibits a stable energy storage properties over a wide temperature range of −70 to 170 °C, with much improved electric cycling reliability up to 10 cycles. [Figure not available: see fulltext.] 3 3 3 2 3+ 4+ 3 5