Provided are a transistor array substrate and an electronic device. A first active layer includes a first area, a second area spaced apart from the first area, and a channel area provided between the first area and the second area. A gate insulating film is disposed on the first active layer. A gate electrode is disposed on the gate insulating film to overlap a portion of the channel area of the first active layer. The gate electrode overlaps a portion of at least one area of the first and second areas of the first active layer. Deteriorations in the channel area are prevented.