As low‐dimensional lead‐free hybrids with higher stability and lower toxicity than those of three‐dimensional lead perovskites, organic antimony(III) halides show great application potential in opt‐electronic field owing to diverse topologies along with exceptional optical properties. We report herein an antimony(III) hybrid (MePPh3)2SbCl5 with a zero‐dimensional (0D) structure, which exhibits brilliant orange emission peaked at 593 nm with near‐unity photoluminescent quantum yield (99.4 %). The characterization of photophysical properties demonstrates that the broadband emission with a microsecond lifetime (3.24 μs) arises from self‐trapped emission (STE). Electrically driven organic light‐emitting diodes (OLEDs) based on neat and doped films of (MePPh3)2SbCl5 were fabricated. The doped devices show significant improvement in comparison to non‐doped OLEDs. Owing to the much improved surface morphology and balanced carrier transport in light‐emitting layers of doped devices, the peak luminance, current efficiency (CE) and external quantum efficiency (EQE) are boosted from 82 cd m−2 to 3500 cd m−2, 1.1 cd A−1 to 6.8 cd A−1, and 0.7 % to 3.1 % relative to non‐doped devices, respectively. A highly luminescent organic antimony(III) hybrid (MePPh3)2SbCl5 featured with STE emission is prepared with good reproducibility and high stability. High‐efficiency OLEDs are demonstrated with this hybrid as an emitter with the luminance of 3500 cd m−2, current efficiency of 6.8 cd A−1 and EQE of 3.1 %, respectively.