An object quantity estimation system 100 includes: a terminal path estimation unit 20 configured to estimate the traveling paths of wireless terminals; an actual quantity-of-people counting unit 30 configured to count the actual quantity of people that are located in each of the fixed points; a terminal detection rate calculation unit 40 configured to calculate the terminal detection rate that indicates a relationship between the quantity of the wireless terminals and the actual quantity of people, for each of the fixed points; and an actual quantity-of-people estimation unit 50 configured to determine priorities of the traveling paths, each of which passes at least one of the fixed points, and sequentially estimate the actual quantity of people having traveled on each traveling path, in descending order of the priorities of the traveling paths, based on the terminal detection rates.