Embodiments of the present disclosure provide an array substrate and a display device. The array substrate includes a plurality of gate lines and a plurality of data lines, the plurality of gate lines and the plurality of data lines crossing one another to bound pixel units and the pixel unites each including a pixel electrode and a thin film transistor, which includes a drain electrode, the array substrate further includes a common electrode line, the drain electrode includes an extension portion and the common electrode line and the extension portion form a light blocking structure together such that an orthographic projection of the light blocking structure on a plane where the pixel electrode is located is located near an edge of the pixel electrode. The array substrate provided by the present disclosure is applied to a display device.