An apparatus (1) for optical inspection of objects (2) comprises: a conveyor (3) configured to transport the objects (2) in succession, each object (2) having a bottom wall (21), which rests on the conveyor (3), and a side wall (22); an inspection station (4), disposed along the conveyor (3); an illuminator (6) mounted above the inspection station (4) to emit a beam of light rays towards the conveyor (3); a first lens (7) configured to transmit a corresponding beam of collimated rays; a second lens (8) configured to make the light rays converge on the side wall (22) of the object (2) to be inspected.