In photography and videography, a matte box is a device attached to the end of a lens in order to prevent light leakage. It performs and mounts essentially the same as a lens hood, but usually includes adjustable fins called French flags.

Another purpose of a matte box is to hold filters in place in front of the lens. Some are supported by two rods that run the length of the camera, while others are supported by the lens itself.

A matte box may have a bellows, a rigid sunshade, or both. If both, the bellows is positioned within the rigid sunshade, having a mask which may be adjusted forward or backward to suit the angle of view of the camera system.