The present invention provides a buffer and an organic light emitting display that employs the buffer. The buffer is installed in a scan driver or a data driver, which generates scan signals and data signals, respectively, to drive the organic light emitting display. The buffer of the present invention is configured of p-channel metal-oxide-semiconductor (PMOS) transistors, and therefore the scan driver or data driver that includes the buffer can be mounted on a display panel. Various arrangements of the PMOS transistors are proposed for the buffer of the present invention. The buffer of the present invention effectively prevents leakage current that could be generated in the circuit of the buffer.