An optical scanning apparatus for scanning a target surface using a plurality of light beams simultaneously along a first direction of the target surface. The apparatus has a light source having a plurality of light emitting elements; an optical deflector to deflect the plurality of light beams coming from the light source; and a scanning optical system to guide the plurality of light beams deflected by the optical deflector to the target surface. The scanning optical system includes a lens, disposed after the optical deflector, having the strongest power in a second direction perpendicular to the first direction. A plurality of scan lines, corresponding to the plurality of light beams deflected by the optical deflector, intersect or contact each other at an optical face of the lens.