A fixing device includes a fixing unit, a power supply unit, a pressure applying unit, and a controller. The fixing unit fixes toner onto a recording medium, using heat generated by a heat generator. The power supply unit supplies power to drive the fixing unit. The pressure applying unit applies pressure to the recording medium in a nip part between the pressure applying unit and the fixing unit. When plural recording media are sequentially transported, the controller controls the power supply unit to supply power during a first time period from when a trailing edge of one of the recording media passes the nip part to when a leading edge of the subsequent recording medium arrives at the nip part, in accordance with a relationship between the first time period and a second time period required to start the supply of power after the supply of power is stopped.