Organic–inorganic hybrid perovskite halide ferroelectric semiconductor materials have received great attention due to their various properties and wide applications. However, currently, most of the reported ferroelectric semiconductor materials are lead-based, while there are a few reports on iron-based organic–inorganic hybrid semiconductor materials. In this study, we have successfully designed and synthesized a novel zero-dimensional organic–inorganic hybrid metal halide semiconductor ferroelectric material: [(CH3)3NCH2CH2CH3] FeBr4 (1), with a high-temperature phase transition point of 390 K and spontaneous polarization (Ps = 7.5 μC cm−2). The typical hysteresis loop and clear ferroelectric domain of compound 1 were obtained, which revealed the ferroelectricity of compound 1. It is worth mentioning that compound 1 showed a rare ferroelectric–ferroelectric phase transition. In addition, compound 1 has an optical bandgap of 1.88 eV and a theoretical bandgap of 1.71 eV, indicating that compound 1 is a high-quality semiconductor material. This work provides some inspiration for the research on lead-free organic–inorganic hybrid metal halide semiconductor ferroelectric materials. [ABSTRACT FROM AUTHOR]