The present invention relates an output buffer and a power amplifier having the same. The output buffer includes a push-pull circuit unit, an output unit, and a driver. The push-pull circuit unit includes transistors connected to each others in a push-pull formation between a high level power voltage and a low level power voltage. The output unit is connected to the high level power voltage and the low level power voltage, and the driver drives the output unit according to a signal from the push-pull circuit unit.