An OLED display and a driving method of an inspection circuit are provided. The OLED display may include a data driver, a scan driver, a driving transistor, a switching transistor, an organic light emitting diode, and an inspection circuit. The data driver and scan driver may apply a data signal and a scan signal. The driving transistor may generate a current corresponding to a voltage supplied to a first electrode and a control electrode. The switching transistor may apply the data signal to the driving transistor. The organic light emitting diode may be electrically connected to the driving transistor. The inspection circuit may include a three-phase inverter circuit having an input and an output terminal. The input terminal may supply a first power voltage to the output terminal when the output terminal decides an output signal regardless of a signal input to the input terminal.