Campsie is a suburb in the state of New South Wales, Australia. Campsie is 11 kilometres south west of the Sydney central business district, on the southern bank of the Cooks River. Campsie is one of the administrative centres of the City of Canterbury-Bankstown.

The Cooks River, a semi-mature tide-dominated drowned valley estuary, is a tributary of Botany Bay, located in south-western Sydney, New South Wales, Australia.