A display apparatus comprising: a first substrate; a scan line that extends in a first direction over the first substrate; a data line that extends in a second direction crossing the first direction; a sensing line that extends in the second direction; a switching transistor electrically connected to the scan line and the data line; a driving transistor electrically connected to the switching transistor; a sensing transistor (M3, M13) electrically connected to the driving transistor and electrically connected to the sensing line; a first insulating layer arranged between the first substrate and a sensing semiconductor layer of the sensing transistor; a via insulating layer provided on the switching transistor, the driving transistor, and the sensing transistor; and a light-emitting diode (OLED1, OLED2, OLED3) including a first electrode, an emission layer, and a second electrode, the first electrode being provided on the via insulating layer, the emission layer being provided on the first electrode, and the second electrode being provided on the emission layer, wherein the sensing line is arranged below the first insulating layer and overlaps the first electrode of the light-emitting diode, wherein the display apparatus further comprises: an auxiliary sensing line that overlaps the sensing line and that is arranged in a same layer as a sensing gate electrode of the sensing transistor. a first substrate; a scan line that extends in a first direction over the first substrate; a data line that extends in a second direction crossing the first direction; a sensing line that extends in the second direction; a switching transistor electrically connected to the scan line and the data line; a driving transistor electrically connected to the switching transistor; a sensing transistor (M3, M13) electrically connected to the driving transistor and electrically connected to the sensing line; a first insulating layer arranged between the first substrate and a sensing semiconductor layer of the sensing transistor; a via insulating layer provided on the switching transistor, the driving transistor, and the sensing transistor; and a light-emitting diode (OLED1, OLED2, OLED3) including a first electrode, an emission layer, and a second electrode, the first electrode being provided on the via insulating layer, the emission layer being provided on the first electrode, and the second electrode being provided on the emission layer, wherein the sensing line is arranged below the first insulating layer and overlaps the first electrode of the light-emitting diode, a scan line that extends in a first direction over the first substrate; a data line that extends in a second direction crossing the first direction; a sensing line that extends in the second direction; a switching transistor electrically connected to the scan line and the data line; a driving transistor electrically connected to the switching transistor; a sensing transistor (M3, M13) electrically connected to the driving transistor and electrically connected to the sensing line; a first insulating layer arranged between the first substrate and a sensing semiconductor layer of the sensing transistor; a via insulating layer provided on the switching transistor, the driving transistor, and the sensing transistor; and a light-emitting diode (OLED1, OLED2, OLED3) including a first electrode, an emission layer, and a second electrode, the first electrode being provided on the via insulating layer, the emission layer being provided on the first electrode, and the second electrode being provided on the emission layer, wherein the sensing line is arranged below the first insulating layer and overlaps the first electrode of the light-emitting diode, wherein the display apparatus further comprises: an auxiliary sensing line that overlaps the sensing line and that is arranged in a same layer as a sensing gate electrode of the sensing transistor.