The development of high-efficiency orange phosphorescent organic light-emitting diodes (PhOLEDs) with reduced efficiency roll-off offers significant benefits, enabling a more simplified method for producing white-OLEDs through the combination of sky blue and orange OLEDs, in contrast to the conventional use of three primary colors. Herein, we have designed and synthesized two hosts with 9-(4-(14H-dibenzo[a,j]xanthen-14-yl)phenyl)-9H-carbazole (XaPCz) and 10-(4-(14H-dibenzo[a,j]xanthen-14-yl)phenyl)acridin-9(10H)-one (XaPAc) derivatives. The singlet and triplet energies for XaPCz and XaPAc are S1 = 3.65, 3.12 eV, and T1 = 2.67, 2.70 eV, respectively. These materials are employed as hosts for orange PhOLEDs using bis(2-phenylquinoline) (acetylacetonate) iridium (III) [Ir(pq)3] as an emitter. XaPCz demonstrates maximum external quantum efficiency (EQEmax) of 20.5%, and XaPAc shows EQEmax of 22.3% with Commission Internationale de l'Eclairage (CIE) coordinates of (0.53, 0.46) and (0.54, 0.45), respectively. In addition, the XaPAc-based device shows a lower turn-on voltage (2.5 V) and high-power efficiency of 60.0 lm/W. More importantly, both device shows reduced roll-off and retain more than 94% of EQEmax at 1,000 cd/m2. The XaPAc-based device maintains an EQE of 17.9% even at 10,000 cd/m2.