Ermington is a suburb of Sydney, New South Wales, Australia. Ermington is located 19 kilometres West of the Sydney central business district, in the local government area of the City of Parramatta. Ermington lies on the northern bank of the Parramatta River.

The City of Parramatta, also known as Parramatta Council, is a local government area located to the west and north-west of Sydney CBD in the Greater Western Sydney region. Parramatta Council is situated between the City of Ryde and Cumberland, where the Cumberland Plain meets the Hornsby Plateau, approximately 25 kilometres (16 mi) west of the Sydney central business district, in New South Wales, Australia. The city occupies an area of 84 square kilometres (32 sq mi) spanning across suburbs in Greater Western Sydney including the Hills District, and a small section of Northern Sydney to the far north east of its area. According to the 2016 census, City of Parramatta had an estimated population of 226,149. The city houses the Parramatta central business district which is one of the key suburban employment destinations for the region of Greater Western Sydney.