The Illawarra district is the name given to a coastal region of New South Wales immediately south of Sydney. Immediately adjacent to the Illawarra to the south is the Shoalhaven region, which partially overlaps it.

The Illawarra district consists of a narrow, hilly, coastal region bounded by the Pacific Ocean on the east and a mountainous, almost impassable escarpment forming the eastern edge of the Southern Highland plateau, to the west. The district extends from Thirroul in the north to Gerringong in the south, and contains the city of Wollongong, the third largest urban area in New South Wales.

The main industries in the area have traditionally been farming, coal mining and steel making. Australia's largest steel works is located at Port Kembla. The Illawarra district is linked to Sydney by motorway and electric railway (see Illawarra Line) and to the interior by Illawarra Highway.

Towns in the Illawarra district include Thirroul, Bulli, Wollongong, Port Kembla, Windang , Dapto, Albion Park, Shellharbour, Kiama, Gerringong, and Jamberoo .