A relief device for an oil pump includes a relief valve including a small diameter valve chamber and a large diameter valve chamber and a valve housing that includes a relief discharge section, a temperature sensitive valve, an oil pump, a main channel, a relief channel, and an auxiliary channel. The relief channel causes one side of the small diameter valve chamber and the large diameter valve chamber and the oil pump to always communicate with each other and enables oil to be discharged from the relief discharge section. The auxiliary channel enables the other one side of the small diameter valve chamber and the large diameter valve chamber and the oil pump to communicate with each other. The temperature sensitive valve is included in the auxiliary channel.