A headrest for an automobile seat has a headrest body and an attachment member to be attached to a back of the seat to allow the headrest body to be moved up and down with respect to the seat back in a standing posture, while allowing the headrest body to be rotated about a pivot shaft to move a lower end of the headrest body in a frontward-rearward direction of the automobile. The headrest body has an expanded rear portion thereof to expand rearwardly and configured so that a distance between the surface of the expanded portion and the pivot shaft gradually decreases toward an upper edge of the expanded portion. The expanded portion is opposed to an upper surface of the seat back in the standing posture and contacts the upper surface when the attachment member is moved down.