In principle, the ratio (Φ) of the maximum quantum efficiencies for electroluminescence (EL) to photoluminescence (PL) can be expected to approach unity, if the exciton (bound electron–hole pair) generated from the recombination of injected electrons and holes in OLEDs has a sufficiently weak binding energy. However, seldom are examples of Φ > 25% reported in OLEDs because of the strongly bound excitons for most organic semiconductors in nature. Here, a twisting donor–acceptor triphenylamine‐thiadiazol molecule (TPA‐NZP) exhibits fluorescent emission through a hybridized local and charge‐transfer excited state (HLCT), which is demonstrated from both fluorescent solvatochromic experiment and quantum chemical calculations. The HLCT state possesses two combined and compatible characteristics: a large transition moment from a local excited (LE) state and a weakly bound exciton from a charge transfer (CT) state. The former contributes to a high‐efficiency radiation of fluorescence, while the latter is responsible for the generation of a high fraction of singlet excitons. Using TPA‐NZP as the light‐emitting layer in an OLED, high Φ values of 93% (at low brightness) and 50% (at high brightness) are achieved, reflecting sufficient employment of the excitons in the OLED. Characterization of the EL device shows a saturated deep‐red emission with CIE coordinates of (0.67, 0.32), accompanied by a rather excellent performance with a maximum luminance of 4574 cd m−2 and a maximum external quantum efficiency (ηext) of ∼2.8%. The HLCT state is a new way to realize high‐efficiency of EL devices. A hybridized local and charge‐transfer state character—identified based on solvatochromic effects, lifetime measurements, and DFT calculations—endows twisting donor–acceptor triphenylamine‐thiadiazol molecules (TPA‐NZP) with a high singlet ratio of nearly 100% in OLEDs. Electroluminescent decay analysis and negative magnetic‐field effects indicate that the reason for the high singlet ratio could be the reverse intersystem crossing (RISC) process in the high‐lying charge transfer (CT)X state