There are disclosed a DC-DC converter and an organic light emitting display including the same. The DC-DC converter includes a first voltage generator that has an inductor and a plurality of transistors, and converts an input voltage into a first voltage and outputs the first voltage to a first output terminal. The DC-DC converter also includes a controller that controls driving of the first voltage generator by supplying a first driving pulse to each transistor of the first voltage generator. In the DC-DC converter, the amplitude of the first driving pulse is adjustable. Accordingly, it is possible to provide a DC-DC converter and an organic light emitting display including the same, which can achieve high power conversion efficiency by change a driving pulse used in a DC-DC converter.