A side-view mirror (or side mirror), also known as a wing mirror, is a mirror placed on the exterior of motor vehicles for the purposes of helping the driver see areas behind and to the sides of the vehicle, outside the driver's peripheral vision (in the "blind spot").

Almost all modern cars mount their side mirrors on the doors—normally at the A-pillar—rather than the wings (the portion of the body above the wheel well).

The side mirror is equipped for manual or remote vertical and horizontal adjustment so as to provide adequate coverage to drivers of differing height and seated position. Remote adjustment may be mechanical by means of bowden cables, or may be electric by means of geared motors. The mirror glass may also be electrically heated and may include electrochromic dimming to reduce glare to the driver from the headlamps of following vehicles. Increasingly, the side mirror incorporates the vehicle's turn signal repeaters. There is evidence to suggest that mirror-mounted repeaters may be more effective than repeaters mounted in the previously predominant fender side location.