An organic light emitting diode display includes a flexible substrate, a semiconductor layer on the flexible substrate, and an overlapping layer. The transistor includes a driving transistor, a second transistor to transmit a data voltage transmitted through the data line to an input electrode of the driving transistor, and a third transistor including a gate electrode connected to the scan line, a first electrode connected to an output electrode of the driving transistor, and a second electrode connected to a gate electrode of the driving transistor. The third transistor includes two transistors connected in series to each other and connected to each other at a third node, the third node is formed in the semiconductor layer, an additional capacitance portion is formed in the semiconductor layer in the vicinity of the third node, and the overlapping layer overlaps the third node and the capacitance portion of the semiconductor layer.