The cup holder includes a base adapted to be fixed to an attached portion; a lid body provided switchably between a closed position and an open position by turning relative to the base, overlapped with the base in the closed position, and supporting the cup from a lower side thereof in the open position; and a holder supported at the base or the lid body through an arm, and moving in association with a turning of the lid body to become a housed state when the lid body is in the closed position, and to become a used state when the lid body is in the open position. The arm includes a support portion controlling the lateral movement of the cup in the used state of the holder.