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Two bipolar host materials3‐CBPyand4‐mCBPyare reported. These hosts are structural analogs of the common host materials CBP and mCBP wherein the phenyl rings have been replaced with pyridines. The two materials possess deep highest occupied molecular orbital (HOMO) and shallow lowest unoccupied molecular orbital (LUMO) levels along with sufficiently high energyS₁andT₁states that make them suitable hosts for yellow emitters in electroluminescent devices. Yellow‐emitting thermally activated delayed fluorescence organic light‐emitting diodes are fabricated using 2,4,6‐tris (4‐(10H‐phenoxazin‐10‐yl)phenyl)‐1,3,5‐triazine (tri‐PXZ‐TRZ) as the dopant emitter with either3‐CBPyor4‐mCBPyemployed as the host. Their device performance is compared to analogous devices using CBP and mCBP as host materials. The pyridine‐containing host devices show markedly improved external quantum efficiencies (EQE) and decreased roll‐off. The 7 wt% tri‐PXZ‐TRZ‐doped device exhibits very low turn‐on voltage (2.5 V for both3‐CBPyand4‐mCBPy) along with maximum external quantum efficiencies (EQE_max) reaching 15.6% (for3‐CBPy) and 19.4% (for4‐mCBPy). The device using4‐mCBPyalso exhibits very low efficiency roll‐off with an EQE of 16.0% at a luminance of 10 000 cd m⁻².