A fixing device includes: a fixing member that fixes a developer image on a recording medium while rotating; an external heating member that heats the fixing member, the external heating member being driven-rotated by rotation of the fixing member while contacting with an outer peripheral face of the fixing member; an oil supply member that supplies oil to a surface of the external heating member; a switching unit that switches between contact and non-contact of the external heating member to the outer peripheral face of the fixing member, the switching unit causing the external heating member to contact with the outer peripheral face of the fixing member after a fixing operation by the fixing member is started; and a rotation mechanism that rotates the fixing member and rotates the external heating member in a state where the external heating member is separated from the fixing member by the switching unit.