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 restaur…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 of the population was actually born in Portugal.