LiNi1/3Co1/3Mn1/3O2 as a promising cathode material in lithium‐ion batteries was synthesized by flash/field‐assisted sintering technique for the first time. This study showed that the current‐limited synthesis of LiNi1/3Co1/3Mn1/3O2 could be carried out at temperatures less than 400°C for only 8 minutes, compared with the conventional pressureless sintering at 850°C for 12 hours. X‐ray diffraction results showed the phase evolution from precursor mixtures to the final LiNi1/3Co1/3Mn1/3O2 products during flash/field‐assisted sintering process and a well‐layered structure without undesirable cation mixing in the as‐formed LiNi1/3Co1/3Mn1/3O2. Combined with the lowered sintering temperatures and reduced sintering time, the excellent electrochemical performance of flash/field‐assisted sintered LiNi1/3Co1/3Mn1/3O2 materials suggested that this technique could be an energy‐efficient approach for the synthesis of lithium‐ion battery cathode materials and other materials requiring high‐temperature heat treatment.