Perovskite ferroelectrics, in which the spontaneous polarization (Ps) is conducive to the separation of photoexcited charge carriers, have shown great potential for self-powered photodetection. Nevertheless, such self-powered ferroelectric photodetectors are mostly dominated by traditional inorganic oxides and exhibit relatively small zero-bias photocurrent, which limit their further application. Herein, we present a wide-bandgap 2D trilayered lead chloride hybrid perovskite ferroelectric, EA4Pb3Cl10 (1, EA = ethylammonium), which shows a notable Ps of ∼4.5 μC/cm2 and a high Curie temperature (415 K) beyond that of BaTiO3 (393 K). Significantly, benefiting from the wide bandgap of 3.39 eV, a self-powered visible-blind ultraviolet (UV) photodetector has been successfully realized, with a zero-bias photocurrent as high as 18.6 μA/cm2, which is nearly 2 orders of magnitude larger than those of mostly conventional inorganic ferroelectrics. As a pioneering study, this work offers an efficient approach for exploring wide-bandgap perovskite ferroelectrics and will excavate their application in the field of self-powered visible-blind UV photodetection.