The invention provides an ignition control device of engine, an internal combustion engine and a motorcycle including the same. The ignition control device includes revolution speed detection means, revolution speed reduction detection means and ignition prevention means. The revolution speed detection means is configured to detect a revolution speed at a given timing in a revolution of the engine. The revolution speed reduction detection means is configured to detect the amount of speed reduction form a previous engine revolution to a present engine revolution based on the detection of the revolution speed detection means. The present engine revolution is defined as an engine revolution in which an ignition is executed. The previous engine revolution is defined as an immediately previousengine revolution from the present engine revolution. The ignition prevention means is configured to prevent the ignition in the present engine revolution when the amount of speed reduction detected by the revolution speed reduction detection means is greater than a predetermined amount.