A fan device and a fan holder are provided. The fan device includes the fan holder and a fan. The fan holder includes a bracket, four ratchet sets, a seat, and a frame. Each of two ends of the bracket is connected to two of the four ratchet sets. The seat is connected to the two of the four ratchet sets arranged to the one of two ends of the bracket. The frame is connected to the other two of the four ratchet sets arranged to the other one of two ends of the bracket. The seat and the frame are rotatable between a use position and a storage position relative to the bracket through the four ratchet sets. The fan is connected to the frame. The seat and the frame are rotated to the storage position, so that the bracket can be arranged on the seat.