A drive transmission apparatus for transmitting a driving force to a rotatable member includes a driving source; a drive pulley for receiving a driving force from the driving source; a driven pulley; a belt, extending around the drive pulley and the driven pulley, for transmitting the driving force from the drive pulley to the driven pulley; and a driving gear for receiving a driving force from the driving source. The apparatus also includes a driven gear for receiving the driving force of the driving gear; a drive transmitting shaft, provided with the driven pulley and the driven gear, for transmitting the driving force to the rotatable member; and a drive transmission mechanism, provided between the driven gear and the drive transmitting shaft, for transmitting the driving force in a rotational direction from the driven gear to the drive transmitting shaft when an angular speed of the driven pulley is lower than an angular speed of the driven gear.