An in-cell touch panel and a display device are disclosed. The in-cell touch panel includes an array substrate provided with a plurality of sub-pixels, and a plurality of gate lines and a plurality of data lines that are disposed on the array substrate, intersected with each other and insulated from each other, a plurality of self capacitive electrodes which are disposed in a same layer and independent of each other, and a plurality of touch lines connecting the self capacitive electrodes to the touch detection chip; the plurality of gate lines and the plurality of data lines are intersected with each other to define the plurality of sub-pixels; each of the sub-pixels includes a pixel electrode and is configured with a long side and a short side; and the touch lines are disposed along the direction of short sides of the sub-pixels.