An ignition device for an internal combustion engine includes an ignition coil designed as a transformer, the secondary winding thereof being designed to connect to a spark plug, an actuatable switch element connected in series with the primary winding of the ignition coil, and a controller connected to the primary winding of the ignition coil and the control input of the switching element. The controller has a voltage converter which provides a supply voltage for the ignition coil at the output thereof and which can be connected to a motor vehicle electrical system voltage, a controllable changeover switch for applying the supply voltage at either positive or negative polarity to the series circuit of the primary winding of the ignition coil and the switching element, depending on a control signal, and a control circuit which generates the control signal based on a phase of the ignition process.