An estimation unit of a visual object tracking apparatus estimates a plurality of estimated bounding boxes and estimated object IDs respectively corresponding to the estimated bounding boxes based on a plurality of predicted bounding boxes and a plurality of detected bounding boxes. For example, the “detected bounding boxes” are “bounding boxes (bounded areas)” detected by a detector in each of a plurality of frames in a time series such as moving images. The “bounding box” is a frame surrounding an image of an object detected in a frame. For example, the “predicted bounding box” is a “bounding box” predicted by a predictor based on an estimated bounding box(es) estimated for one or a plurality of frames in the past.