A fingerprint sensor for a display device includes a light sensing layer including a light sensing element, and an optical layer including a light transmitter disposed in a light-transmitting area and a light blocker disposed in a light-blocking area. The light-transmitting area includes a plurality of unit light-transmitting areas separated by the light-blocking area, and each of the unit light-transmitting areas has a first width and the light-blocking area has a second width, the first width being in a range of about 5 times to about 200 times the second width.