A light scanning apparatus includes a light source, a deflector configured to deflect a light flux from the light source, and an imaging optical system configured to guide the light flux deflected at the deflector onto a scanned surface. The imaging optical system consists of a single imaging optical element, wherein, on the optical axis of the imaging optical system, the conditions 0.15≦T2/Sk≦0.3 and 0.03≦d/K≦0.08 are satisfied. A condition 0.3≦B≦0.6 is satisfied at a condensing position Y where a scanning angle θ is greatest, when the condensing position Y in the main scanning direction on the scanned surface of the light flux deflected at the scanning angle θ by the deflector is expressed by Y=(K/B)×tan(B×θ).