An air-conditioning ventilation system of the present invention includes one or a plurality of air circulation devices configured to circulate air among a plurality of rooms, one or a plurality of air-conditioning apparatuses provided in at least one of the plurality of rooms, a human detector provided in each of the plurality of rooms and configured to detect a human present in a corresponding one of the rooms in which the human detector is provided, an optimal air-conditioning ventilation operation estimating unit configured to estimate presence or absence of any human in each of the plurality of rooms, or a human presence ratio representing a number of humans present per unit time in each of the plurality of rooms, on a basis of a past result of detection by the human detector, and a controller configured to control the air circulation device and the air-conditioning apparatus on a basis of a result of estimation by the optimal air-conditioning ventilation operation estimating unit.