Two deep-red/near-infrared (NIR) iridium phosphors, (fldpqx)2Ir(acac) and (thdpqx)2Ir(acac), were rationally designed and synthesized considering the emission wavelength, emission efficiency, and solubility. In optimized solution-processed phosphorescent polymer light-emitting devices, the (fldpqx)2Ir(acac)-based device achieved a maximum external quantum efficiency of 5.7% with the emission peak at 690 nm, while the (thdpqx)2Ir(acac)-based device achieved a maximum external quantum efficiency of 3.4% with the emission peak at 702 nm, which are comparable to the highest values ever reported for solution-processable NIR emitters. Moreover, these devices merely experienced low efficiency roll-off at high current densities.