A lens driving actuator includes an upper cover having an opening for passing light, a lens barrel arranged in the upper cover and including a light-transmitting lens, a driving pin formed on an outer circumferential surface of the lens barrel, a driving cam member formed to cover the outer circumference of the lens barrel, and having a cam groove that engages with the driving pin, and a driving source configured to supply a driving force to a gear formed in the driving cam member. When the driving cam member rotates along the outer circumferential surface of the lens barrel, the driving pin is guided by the cam groove, and the lens barrel moves in an optical-axis direction with respect to the upper cover.