A display apparatus including: a substrate including a main display area and a sensor area, the sensor area including an auxiliary pixel and a transmission portion, wherein the main display area includes a main pixel; a sensor disposed in the sensor area and configured to transmit a signal through the substrate and the transmission portion, wherein the auxiliary pixel includes an auxiliary light-emitting device including an auxiliary cathode layer, and wherein the auxiliary cathode layer includes a plurality of layers partially overlapping each other at a first overlapping portion thereof, wherein the auxiliary cathode layer does not cover the transmission portion.