An optical apparatus includes a magnification-varying lens, a controller configured to control an actuator, and to move the magnification-varying lens; and a temperature detector configured to detect a temperature of the optical apparatus, wherein the controller sets a telephoto end position of the magnification-varying lens to a first position when the temperature detected by the temperature detector is a first temperature, and the controller sets the telephoto end position of the magnification-varying lens to a second position closer to a wide-angle side than the first position when the temperature detected by the temperature detector is a second temperature higher than the first temperature.