An array substrate and a display device are provided. The array substrate includes a display region and a peripheral circuit region, wherein a first gate line, a first data line and a pixel region are arranged in the display region; the pixel region includes a first pixel electrode and a thin film transistor, and the thin film transistor includes a first gate electrode, a first source electrode and a first drain electrode; the peripheral circuit region is provided with at least one test unit including: a second gate line; a second data line; a second testing pixel electrode; and a second testing thin film transistor. The second testing thin film transistor includes a second gate electrode, a second source electrode and a second drain electrode, wherein the second gate electrode, the second source electrode and the second drain electrode are provided with test ports exposed outside.