Evidence of Aboriginal occupation of the land now known as Oatley exists in the form of numerous shell middens and rock shelters near the shore of Georges River.[2]

This suburb's name can be traced to James Oatley Snr, watch-maker, who was transported to Botany Bay for life in 1814. Seven years later, in 1821, Governor Lachlan Macquarie granted Oatley a conditional pardon and appointed him overseer of the Town Clock for his work in installing the clock at Hyde Park Barracks.[3][4]

On 17 August 1898, Oatley was the site of a pursuit and gun battle involving a party of police and George Peisley (or Peasley), a fugitive cattle and horse thief, who was using a sandstone cave on the eastern side of Gungah Bay as his hide out.[5] Peisley escaped capture,[6] but was arrested at Arncliffe on the following day[7] and eventually sentenced to four years hard labour.[8]

The post office opened in 1903, thus giving the district its official name of Oatley. Prior to this, the area west of the railway line was officially in the suburb of Hurstville and attached to the Hurstville Post Office with "Oatley's" in parenthesis at the end of the address. Likewise, the streets east of the railway line were officially in the suburb of Kogarah and attached to the Kogarah Post Office. In the late 1890s both Hurstville and Kogarah were much larger suburbs and were later divided up into separate suburbs.

Oatley is notable as the terminus of the first railway electrification project in Sydney, which reached this station from Sydney Central in 1926  (Wikipedia)