An inter-moving body interferometric positioning system for carrying out positioning in coordination with three or more moving bodies that can mutually communicate, including: a reference vehicle decision unit for deciding on a single moving body to function as a reference vehicle from among three or more moving bodies, and a positioning unit for interferometrically determining respective relative positions of other moving bodies relative to the reference moving body that is to function as a reference vehicle decided on by the reference moving body decision unit using satellite wave monitoring data monitored in each of the three or more moving bodies. This inter-moving body interferometric positioning system specifies relative positions among the other moving bodies using positioning results of the positioning unit.