Disclosed is a luminaire such as an LED downlight which is suitable for mounting in ceiling cavities of commercial environments. An example luminaire (200) comprises a light source (202) including an integral primary optic which is configured to transmit light toward a second optic (214). The second optic (214) is a lens configured to receive light from the light source (202) via the primary optic and transmit at least part of the received light toward a circular reflector (201). The circular reflector (201) is configured to direct light received from the second optic (214) away from the luminaire (204). A shape of the second optic (214) is interdependent with a shape of the circular reflector (201), and the shape of the second optic (214) and circular reflector (201) act in combination to transmit light away from the luminaire with a non-circular illuminance distribution (206).