An organic light emitting display capable of improving data charging time, includes pixels at crossing regions between scan and data lines and configured to control an amount of current supplied from a first to a second power source, a charge unit adjacent to an adjacent pixel of the pixels and coupled to the same data line as the adjacent pixel, a scan driver for supplying scan signals to the scan lines, a data driver for supplying data signals to the data lines in synchronization with the scan signals, and a comparison unit in a channel of the data driver to compare a data signal supplied to a current line with a data signal supplied to a previous line and to control coupling between the charge unit and the data line according to a comparison result in a partial period of a period in which the scan signals are supplied.