A triarylboryl-functionalized oxadiazole compound, 2,5-bis-(m-dimesitylboryl-phenyl)-1,3,4-oxadiazole (1) was prepared and characterized to investigate multi-functional properties in phosphorescent OLEDs (PhOLEDs). X-ray crystal structure revealed that two Mes2B groups are oriented toward the same side and the entire fragments of oxadiazole, phenylene, and trigonal boron are in a nearly coplanar arrangement. From the optical and electrochemical measurements, 1 was shown to possess high triplet energy (E T = 2.75 eV) and deep HOMO (E HOMO = 6.02 eV) and low LUMO levels (E LUMO = 2.53 eV), which are suitable for electron transporting (ETM) and/or host materials in PhOLEDs. Green PhOLED devices incorporating 1 as electron transporting material (ETM), host, or host/ETM were fabricated and compared their performance with that of the devices based on the well-known CBP (9,9′-(1,1′-biphenyl)-4,4′-diylbis-9H-carbazole) host and TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene) ETM. Among them, the devices based on 1 as host/ETM showed the highest performance that is comparable to that of the reference device.