An in-cell touch panel includes: transistors and pixel electrodes respectively provided in pixels; common electrodes arranged in a first direction and a second direction, each facing one or more of the pixel electrodes and provided separately from each other; gate lines extending along the first direction; data lines extending along the second direction; dummy data lines extending along the second direction, provided in a same layer as the data lines; and touch lines extending along the second direction and connected to a corresponding one of common electrodes. The data lines and the dummy data lines are alternately provided for boundaries between two pixels adjacent in the first direction.