An optical system includes, in order from a pupil surface side to a display surface side, a first reflective polarizing plate, a first lens having a positive refractive power, a half mirror, a second lens having a positive refractive power, and a second reflective polarizing plate. The optical system further includes a first quarter wave plate arranged between a pupil surface and the half mirror, and a second quarter wave plate arranged between the half mirror and a display surface. The second lens has a paraxially convex surface on the pupil surface side. Further, in the case where a paraxial curvature radius of a surface of the first lens on the pupil surface side is r1 and a paraxial curvature radius of a surface of the first lens on the display surface side is r2, the optical system satisfies a conditional expression below: (1) −3.2