A tire abnormality determination system (100) of the present disclosure includes: a related information acquisition portion (111) that acquires deterioration-related information that may exert influence on deterioration of a non-pneumatic tire (1) mounted on a vehicle (50); a first determination processing portion (112) that determines, based on the deterioration-related information, at least one of presence or absence of a sign of an abnormality in the non-pneumatic tire (1) and presence or absence of the abnormality in the non-pneumatic tire (1); and an output processing portion (115) that outputs a first determination result of the first determination processing portion (112) to a predetermined output destination.