Petersham is a suburb in the Inner West of Sydney, in the state of New South Wales, Australia. Petersham is located 6 kilometres south-west of the Sydney central business district, in the local government area of Inner West Council. Petersham is known for its extensive Portuguese commercial offerings, with many Portuguese businesses and restaurants, although only 156 (1.9%) of the population was actually born in Portugal.

The Inner West of Sydney is an area directly west of the Sydney central business district, New South Wales, Australia. The suburbs that make up the Inner West are predominantly located along the southern shore of Port Jackson, stretching south to the shores of the Cooks River. The western boundary of the Inner West is approximately the A3 arterial road, which divides the Inner West from the Greater Western Sydney region. The Inner West is much larger than the Inner West Council local government area. The Inner West roughly corresponds with the Parish of Petersham and Parish of Concord, two cadastral divisions used for land titles.