A touch sensor includes a substrate, an insulating layer, a sensor, and sensing lines. The substrate includes: a sensing region, and a peripheral region at a periphery of the sensing region. The insulating layer is on the substrate. The insulating layer includes contact holes. The sensor is on the substrate and overlaps the sensing region. The sensing lines are on the substrate and overlap the peripheral region. The sensing lines are connected to the sensor. Each of the sensing lines is formed as a multilayer structure. The multilayer structure includes a first electrically conductive layer on the substrate, and a second electrically conductive layer connected to the first electrically conductive layer via a contact hole among the contact holes. Widths of the sensing lines are different from one another.