The present invention provides a position estimation apparatus, mounted at mobile object, including: an acquisition section that acquires transmission source information transmitted from each plural information transmission sources including, information relating to a position of information transmission source, information relating to a distance between information transmission source and mobile object, and information relating to a relative velocity of mobile object with respect to information transmission sources; a trajectory calculation section that calculates, over predetermined duration, a trajectory of mobile object by integrating velocity vectors of mobile object obtained based on transmission source information; and an estimation section that estimates, as a position of mobile object, a position for which trajectory is translated such that a difference between, distances between a plurality of points at different times on trajectory and respective information transmission sources, and acquired distances between respective information transmission sources and mobile object, is minimum.