A supply device includes: a loading portion where recording media are loaded; a transport unit to transport the media; a contact portion provided on the loading portion, the contact portion being in contact with a side end portion of the media having a first size in a direction intersecting with a transport direction, the contact portion having a blowing portion to blow air to the side end portion; a guide portion detachably attached to the contact portion when media having a second size smaller than the media having the first size are loaded, the guide portion being configured to guide a side end portion of the media having the second size; and a duct provided in the guide portion, the duct including a discharge port to blow the air from the blowing portion to an upper end portion of the media having the second size loaded on the loading portion.