An image forming apparatus includes a fixing portion, a sheet conveying portion, a first airflow generating portion, a setting processing portion, and a first drive processing portion. The fixing portion heats a sheet on which a toner image has been transferred to fix the toner image to the sheet. The sheet conveying portion conveys a sheet along a conveyance path that leads to a sheet discharge port via the fixing portion. The first airflow generating portion includes a first fan and generates an airflow flowing upstream from the fixing portion in a conveyance direction of the sheet. The setting processing portion sets a drive speed of the first fan based on either or both of a sheet size, and a conveyance interval at which the sheet conveying portion conveys the sheet. The first drive processing portion drives the first fan at the drive speed set by the setting processing portion.