A gas turbine engine includes a turbomachine and a fan rotatable by the turbomachine. The fan includes a plurality of fan blades. The gas turbine engine also includes an outer nacelle surrounding the plurality of fan blades and including an inner wall, the inner wall of the outer nacelle including a plurality of pre-swirl contours positioned forward of the fan blades of the fan along an axial direction and extending inwardly along a radial direction.