A communication system is a communication system provided in a mobile body and including an acquirer configured to acquire a destination of the mobile body and a position of the mobile body, and a communicator configured to communicate with a communication device outside the mobile body using an antenna, in which the communicator is configured to set a reception sensitivity of the antenna when the position of the mobile body approaches to within a predetermined distance from the destination of the mobile body to be higher than a reception sensitivity of the antenna before the position of the mobile body approaches to within the predetermined distance.