An organic light emitting diode (OLED) display that includes a first substrate having a display area, a photo sensor arranged on a first substrate external to the display area, and a condensing lens arranged at an upper portion of the photo sensor to condense external light into the photo sensor, allowing the photo sensor to more efficiently detect an amount of external light. In this OLED display, an automatic luminance control function can be efficiently performed by increasing a condensing efficiency of the photo sensor.