A touch sensor includes: a plurality of sensor pixels; a sensor scan driver for supplying sensor scan signals to the sensor pixels through sensor scan lines; a power supply unit for supplying common voltages to the sensor pixels through common lines; and a read-out circuit connected to the sensor pixels through the common lines, the read-out circuit configured to sense a touch by using an output signal output through the common lines, wherein two sensor pixels adjacent to each other among the sensor pixels share one common line.