A thin film transistor array panel includes: a gate line disposed on a substrate and including a first connection member of a gate driver region and a gate electrode of a display area, a gate insulating layer disposed on the substrate and having a first contact hole exposing the first connection member, a semiconductor layer disposed on a region of the gate insulating layer, a data line disposed on the gate insulating layer and the semiconductor layer and including a drain electrode, a source electrode, and a second connection member connected to the first connection member through the first contact hole, a passivation layer disposed on the data line, the source electrode, the drain electrode, and the second connection member, and a pixel electrode disposed on the passivation layer and electrically connected to the drain electrode. A horizontal width of the first contact hole ranges from 1 to 2 μm.