Disclosed is an organic light emitting display of improved an image quality. The organic light emitting display includes a frame memory for storing a data to correspond to a write clock and outputting the data stored according to a read clock; a signal generation unit for supplying the read clock; a data driver for converting the data, supplied from the frame memory, into a data signal and supplying the converted data signal to data lines; a scan driver for supplying a scan signal to scan lines; and pixels arranged near crossing points between the scan lines and the data lines, wherein the read clock has a higher frequency than the write clock.