A touch sensor includes a panel including display pixels and sensing nodes, a touch-sensing block configured to sense a change in capacitance of the sensing nodes, and a timing controller configured to generate state information based on a polarity of data and/or an inflow of electrostatic discharge to the panel and/or a peripheral temperature and/or an on or off state of the panel. The touch-sensing block senses a presence or absence of a touch on or over the sensing nodes based on the state information and the change in capacitance of the sensing nodes.