In an optical head device and an optical disc device, which make it possible to reduce an influence of a differential push-pull signal by stray light without making the structure complicated, reflective light of zero-order diffracted light by other information recording surfaces than an access subject information recording surface, reflective light of + first-order diffracted light by other information recording surfaces than an access subject information recording surface, and reflective light of - first order-order diffracted light by other information recording surfaces than an access subject information recording surface form an interference fringe on an optical detector (9). If a length in a y-direction of one period of the interference fringe is Ty, a positive integer is N1, and lengths in the y-direction of divided receiving elements (9e, 9f, 9g, 9h) are Uy, respectively, then they satisfy the following: Uy=Ty x N1. Further, if a positive integer is N2, a distance from the center of a main beam light receiving unit (9M) to the divided receiving elements (9e, 9f, 9g, 9h) and a distance from the center of the main beam light receiving unit (9M) to a dividing line of the divided receiving elements (9g, 9h) are Vy, then they satisfy the following: Vy = (Ty/2) x {N2 - (1/2)}.