A lens assembly includes a lens including an optical portion to refract light and a flange portion extended along a periphery of at least a portion of the optical portion, and a lens barrel to accommodate the lens. The flange portion has a non-circular shape and includes a first di-cut portion on a first side surface of the flange portion, a second di-cut portion on a second side surface of the flange portion, and arc portions connecting the first di-cut portion and the second di-cut portion. A first distance between the first di-cut portion and an optical axis of the lens and a second distance between the second di-cut portion and the optical axis of the lens are smaller than a distance between respective opposite ends of the arc portions and the optical axis.