Provided are a mobile body such as an automatic guided vehicle (AGV) that can be introduced and used at a low cost, and a system for controlling the mobile body. A mobile body guidance system for guiding the mobile body has: the mobile body; a positioning device for measuring the position of the mobile body and outputting position information of the mobile body; and a guidance device for guiding the mobile body. When the guidance device guides the mobile body from a first position via a second position to a third position, the guidance device transmits a first guidance command for guiding the mobile body from a first position to a second position. While the mobile body is moving from the first position to the second position in accordance with the first guidance command, the guidance device estimates an expected arrival position of the mobile body on the basis of the changes in position of the mobile body measured by the positioning device. The guidance device generates a second guidance command for guiding from the estimated arrival position to the third position, and before the mobile body arrives at the estimated arrival position, transmits the second guidance command to the mobile body at least once.