Stereo Camera, Onboard Lighting Unit, and Stereo Camera System

To reduce size and cost of a stereo camera and an onboard lighting unit. A stereo camera includes a first convex hyperboloidal mirror and a second convex hyperboloidal mirror that share a central axis and are vertically disposed with vertexes facing each other, an imaging optical system, and an image sensor. The second convex hyperboloidal mirror is formed of an outer circumferential hyperboloidal mirror and an inner circumferential hyperboloidal mirror that share the central axis with different conic constants, and an absolute value of the conic constant of the inner circumferential hyperboloidal mirror is greater than an absolute value of the conic constant of the outer circumferential hyperboloidal mirror.