A sheet feeding apparatus, in which a feeding roller can take a feeding and retracted positions through a simple configuration, and an image reading apparatus, and an image forming apparatus including the same. The sheet feeding apparatus includes an original stack tray, a pickup roller, a pickup arm, a separation shaft of a separation roller which is connected to the pickup roller and rotates the pickup arm, a driving motor which is connected to the shaft, and a weight member which is supported to the pickup arm on a side opposite to the pickup roller. When the driving motor is driven, the pickup arm is rotated to a feeding position to feed an original. When transmission of a driving to the shaft is blocked, the pickup roller is rotated to a retracted position by the weight member.