A pixel of an organic light emitting display includes first through fourth transistors and a capacitor. The first transistor operates based on a scan signal and is connected between a data line and a first node. The capacitor is connected between the first node and a second node. The second transistor operates based on a gate signal and is connected between a first power voltage and a third node. The third transistor operates based on compensation control line signal and is connected between the second node and the third node. The fourth transistor operates based on sensing control line signal and is connected between the data line and the third node. The organic light emitting element is connected between the third node and a second power voltage.