A thin film transistor which may be included in a pixel circuit includes: a substrate; a semiconductor layer formed on the substrate and including a source region, a first drain region spaced apart from the source region by a first current path, and a second drain region spaced apart from the source region by a second current path having a length different from that of the first current path; a gate electrode insulated from the semiconductor layer by a gate insulating layer; a source electrode connected to the source region of the semiconductor layer; a first drain electrode connected to the first drain region of the semiconductor layer; and a second drain electrode connected to the second drain region of the semiconductor layer. Currents having different magnitudes may be simultaneously provided through the first current path and the second current path.