An optical scanning apparatus includes a light source configured to emit a light beam, a scanning unit configured to deflect the light beam from the light source so as to scan a photosensitive member, an optical lens configured to guide the light beam scanned by the scanning unit onto the photosensitive member, and a lens supporting unit having a fixing portion configured to fix the optical lens, wherein the lens supporting unit includes a movable supporting portion configured to restrict movement of the optical lens in a direction perpendicular to a scanning direction of the light beam and an optical axis direction of the optical lens, to restrict movement of the optical lens in the optical axis direction, and to support the optical lens movably in the scanning direction.