Disclosed is a display device with a built-in touch screen. The display device includes a gate electrode and a pixel electrode on a substrate, an activation layer and a sensing contact portion, a source electrode and a drain electrode, and a gate insulation layer provided between the gate electrode and the activation layer and between the pixel electrode and the sensing contact portion. Thereby, it is possible to reduce the number of data lines arranged in the display panel. Also disclosed is a method of fabricating a display device with a built-in touch screen. The method includes forming a first gate electrode and a pixel electrode according to a first mask process, and forming an activation layer, a source electrode, a drain electrode, and a touch sensing line according to a second mask process. Thereby, it is possible to reduce the number of mask processes.