A light guide includes: a body which is a light-transmitting member and has light incidence surfaces as two end surfaces in a longitudinal direction and a light output surface which is one of side surfaces extending in the longitudinal direction; and light absorbing members which are provided on the light output surface or at least one, adjacent to the light output surface, of the side surfaces of the body and have a function of absorbing light that shines on the body from outside the body.