A thin film transistor array panel includes: a data line which extends in a column direction and transfers a data voltage; a first pixel electrode and a second pixel electrode connected to the data line and adjacent in a row direction; a first thin film transistor connected to the first pixel electrode and the data line, and including a first source electrode and a first drain electrode; and a second thin film transistor connected to the second pixel electrode and the data line, and including a second source electrode and a second drain electrode. The first pixel electrode is at the right of the data line, the second pixel electrode is at the left of the data line, and relative positions of the first source electrode and the first drain electrode are the same as relative positions of the second source electrode and the second drain electrode.