A display apparatus includes a thin film transistor on a first base substrate, the thin film transistor including a gate electrode disposed on the first base substrate, an active pattern disposed on the first base substrate and including a semiconductor layer including of amorphous silicon and an ohmic contact layer which is on the semiconductor layer, a drain electrode disposed on the ohmic contact layer and having a first thickness, and a source electrode disposed on the ohmic contact layer and having a second thickness which is greater than the first thickness.