Provided is an object conveying system including: a conveying apparatus that conveys an object; one or more cameras that capture images of feature points of the object; a position measuring portion that measures positions of the feature points from the acquired images; a detecting portion that detects a position or a movement velocity of the object; a position correcting portion that corrects the positions of the feature points so as to achieve positions at which the feature points are disposed at the same time; a line-of-sight calculating portion that calculates lines of sight that pass through the feature points on the basis of the corrected positions of the feature points and the positions of the cameras; and a position calculating portion that calculates a three-dimensional position of the object by applying a polygon having a known shape to the calculated lines of sight.