The present invention provides an imaging device and a focusing control method capable of enhancing accuracy of moving subject estimation while reducing the computation of the moving subject estimation used in a case of continuously performing focusing with respect to the moving subject. A system control unit (11) predicts a subject distance in an imaging process of a third frame from information about subject distances obtained in an imaging process of a first frame and an imaging process of a second frame, calculates an error with respect to the predicted subject distance from information about a maximum error with respect to a focus lens position to be calculated, and performs lens driving based on a predicted focus lens position instead of a focusing control based on the predicted subject distance in a case that the error of the subject distance is large.