A ternary inverter is demonstrated based on an organic antiambipolar transistor (AAT), in which the output logic states can be precisely controlled with appropriate optical signals. First, the photoresponse of AATs consisting of PTCDI‐C8 and α‐6T layers is systematically investigated. Under visible light, the Λ‐shaped transfer curve of the AATs undergoes a noticeable broadening due to the optically induced threshold voltage shift in both the PTCDI‐C8 and α‐6T controlled ranges. Under ultraviolet light, broadening is observed only on the α‐6T side. These contrasting impacts of the two light signals enable to tune the balance of the ternary logic states in the inverters, including the output voltage levels and the ratio of the respective logic states. Such optically controlled ternary logic circuits possess great potential for their application in next‐generation optoelectronic devices.