An array substrate and a display device is disclosed. The array substrate includes a base substrate, a plurality of gate lines and a plurality of data lines arranged to intersect each other on the base substrate, a pixel electrode arranged in a region defined by an adjacent gate line and an adjacent data line, and a thin film transistor arranged at an intersection of the gate lines and the data lines. A drain of the thin film transistor is connected with the pixel electrode through a via hole. The gate lines further include a widening portion between adjacent data lines. The widening portion comprises a recess structure. An orthogonal projection of the recess structure on the base substrate at least partly overlaps that of the drain of the thin film transistor on the base substrate.