Thirroul is a northern seaside suburb of the city of Wollongong, Australia. Situated between Austinmer and Bulli, it is approximately 13 kilometres north of Wollongong, and 73 km south of Sydney. It lies between the Pacific Ocean and a section of the Illawarra escarpment known as Lady Fuller Park, adjacent to Bulli Pass Scenic Reserve.

The Illawarra escarpment, or officially the Illawarra Range, is the fold-created cliffs and plateau-eroded outcrop mountain range west of the Illawarra coastal plain south of Sydney, in the state of New South Wales, Australia. The range encloses the Illawarra region which stretches from Stanwell Park in the north to Kiama, Gerringong and the Shoalhaven River in the south.