A thin film transistor substrate includes: a substrate, a first electrode disposed on the substrate, a bank disposed on the substrate and having an inclined surface inclined at an angle with respect to the substrate, a second electrode disposed on the bank, an active pattern electrically connected to the first electrode and the second electrode, disposed on the inclined surface, and including a first conductive region and a second conductive region in which impurities are doped, and a channel region between the first conductive region and the second conductive region, and a gate electrode overlapping at least a portion of the channel region of the active pattern. The inclined surface extends in a first direction in a plan view. The first conductive region, the channel region, and the second conductive region are sequentially disposed on the inclined surface along a second direction that crosses the first direction.