A collected developer conveying device includes: a conveying passage through which collected developer is conveyed; a conveying member that is disposed in the conveying passage, and conveys the developer in the conveying passage by rotation thereof; a developer carrying body that holds developer on a surface thereof, and that is relatable; and a ventilation passage through which air passes from a developing container including the developer carrying body, wherein the conveying passage includes an air flow region formed in a part thereof upper than a rotational center of the conveying member in a gravitational direction, in a side of the conveying passage in which the conveying member rotates from an upper part of the conveying passage to a lower part thereof in the gravitational direction.