A display device includes: a demux circuit portion including: a first transistor including a part of a first lower gate pattern, a second transistor including a part of a second lower gate pattern, a first control line connected to the first lower gate pattern and supplying a first lighting test control signal or a first demux control signal, and a second control line connected to the second lower gate pattern and supplying a second lighting test control signal or a second demux control signal, and a lighting circuit portion connected to the demux circuit portion and including: a third transistor including another part of the first lower gate pattern and receiving the first lighting test control signal or the first demux control signal, and a fourth transistor including another part of the second lower gate pattern and receiving the second lighting test control signal or the second demux control signal.