To provide an optical coupler in which the increase in the cost of components necessary for the optical coupler is suppressed as far as possible, upsizing is prevented and the influence of chromatic aberration is reduced, and to provide an image display apparatus.

Used optical coupling collimator lenses 13, 13 and 13 have a same focal length, the distances d between the optical coupling collimator lenses 13, 13 and 13 and the emitting end positions of optical coupling optical fibers 8, 8 and 8 are set in such a way that the distance d1 related to R-luminous flux is equal to the focal length of the optical coupling collimator lens 13, and the distance d2 related to G-luminous flux is a prescribed distance longer than the distance d1, and the distance d3 related to B-luminous flux is a prescribed distance longer than the distance d2.