In an organic light emitting diode (OLED) display device and a method for fabricating the same, OLED pixels are patterned through a photolithography process, so a large area patterning can be performed and a fine pitch can be obtained, and an organic compound layer can be protected by forming a buffer layer of a metal oxide on an upper portion of the organic compound layer or patterning the organic compound layer by using a cathode as a mask, improving device efficiency. In addition, among red, green, and blue pixels, two pixels are patterned through a lift-off process and the other remaining one is deposited to be formed without patterning, the process can be simplified and efficiency can be increased.