The present disclosure discloses a thin film transistor assembly, an array substrate and a method of manufacturing the same, and a display device including the array substrate. The array substrate includes a substrate; a plurality of thin film transistors formed on the substrate; and a plurality of light shielding layers, each of the light shielding layers being arranged between a source electrode and a drain electrode of the thin film transistor and configured to block light from the exterior from illuminating an active layer of the thin film transistor. The light shielding layer and the source electrode and the drain electrode of the thin film transistor are formed in the same layer on the substrate. As the light shielding layer, the source electrode and the drain electrode of the thin film transistor and a data line may be formed on the substrate by using the same material layer through a single patterning process, times of performing patterning processes and the number of masks used may be reduced and thus manufacturing process and cost of the array substrate may be decreased.