19th century In 1877, the station opened as the western end of the
Gippsland railway line, it received its current location in 1879, when the line was extended to
South Yarra railway station. In 1883, the track was
duplicated from
Caulfield to Oakleigh, and in 1891, the line was duplicated to
Dandenong. In 1888, the Rosstown line opened, with Oakleigh being the eastern terminus. Two years later, the outer circle line opened from Oakleigh to Waverley Road station.
20th century In , the station featured two
side platforms with an additional centre track. By this time, the station was controlled by two
signal boxes; "A" at the city end, controlling the
Warrigal Road level crossing and
interlocked gates, and "B", between the station and
yard, controlling the latter. In 1915, a new station building had been constructed to the same style as
Box Hill,
Caulfield,
Essendon,
Heidelberg and
Spotswood in the Melbourne area, and
Castlemaine and
Warragul in the country. A new platform was provided on the south side, plus a fifth track for engines to run around their consists. In March 1922,
electrification was extended from Caulfield to Oakleigh, and this was extended to Dandenong during December of that same year. Around the same time, the Hanover Street bridge was built across the Dandenong end of the
goods yard, with alterations to the passenger
sidings and the
run-around loop south of the station was abolished.
Three-position signalling was extended from
Carnegie to the city end of Oakleigh (exclusive) in December 1940. Extension of the signalling to
Huntingdale and
Clayton, in lieu of
Winters Double Line Block safeworking, did not occur until 1970, in conjunction with the North Road (Huntingdale)
grade separation project. In 1968, the Warrigal Road level crossing was closed, and, in conjunction with the demolition of shops, a new road
overpass was provided. The original Warrigal Road surface was partially retained as a slip lane to serve a handful of shops along the western boundary. The road bridge piers were spaced to allow extension of the track from the southernmost platform in the citybound direction. In May 1972, a van that was on the 18:40 Traralgon goods train, which was shunting in the goods yard, derailed. This necessitated single line working on the Up line between Oakleigh and Caulfield, with buses used to convey passengers around the derailment site. In 1975, the track layout was drastically simplified. Both signal boxes were abolished and demolished, being replaced with a new, experimental route-setting power interlocking system located in the middle of the southern station building. In lieu of the older system with individual levers, switches or buttons for each
signal and turnout or
crossover, the new
panel used custom circuit boards and a button arrangement where the operator would select a route between any two signals, and that route would be requested, set and locked by the relay interlocking if available. A 1972 report by BITRE indicated that the project would cost $330,000, and save $26,000 per year in staffing costs, plus avoiding $10,000 expected in upcoming overhaul costs for the existing mechanical systems, with a total benefit/cost ratio over 40 years of 1.7:1 at 7% discount rates or 1.3 at 10% discount rates. In practice, the new interlocking lasted 43 years. The new signal panel included a "switch out" feature, allowing the station's signalling to operate automatically during periods of reduced traffic. To facilitate this, the
island platform was used for most trains, with high-speed (initially 40 mph, later reclassed as 65 km/h) diverge turnouts provided at either end to avoid trains slowing down significantly for the diverging movements. Station staff operated the signal panel during busier times to allow access to or from the goods yard, terminating trains, or overtaking moves in either direction. The new signal panel included a "switch out" feature, allowing the station's signalling to operate automatically during periods of reduced traffic. To facilitate this, the
island platform was used for most trains, with high-speed (65 km/h, 40 mph) turnouts provided at either end to avoid trains slowing down significantly for the diverging movements. Station staff operated the signal panel during busier times to allow access to or from the goods yard, terminating trains, or overtaking moves in either direction. While the panel was switched out, express trains through Oakleigh were assumed to run express through
Hughesdale,
Murrumbeena and Carnegie as well, and given altered level crossing timings; while the panel was switched in this selection had to be made manually. On 8 May 1981, a train entering service from Oakleigh sidings derailed, blocking the morning peak hour services. This trapped the following school train from
Moe, so a
Harris train was run "wrong line" (backwards relative to normal procedures) and parked parallel, with students transferring carefully between the two. A similar incident occurred on 26 January 1982, as a train exiting siding "C" passed signal 38 at Clear Low Speed but 30 at Danger, derailing on the catch points and obstructing the citybound track from around 9am. The train was rerailed by 5:30pm, but one of the cranes used in the operation became bogged while exiting the worksite. On Friday 4 December 1981,
The Overland train service was stabled in Oakleigh due to an industrial dispute. In May 1984, the goods yard was officially closed to traffic, with the exception of
briquette traffic, which was still being received. Way and Works waggon
HD205, which had been parked at the city end of the through siding for years, was transferred to the Caulfield depot on 22 June 1984. By October that year, the briquette traffic had also shifted to
Westall. The overhead in siding "A" was removed by December of that year, along with the
points and the majority of the sidings. In March 1987, a guards' indicator light was provided for signal post 16, controlling citybound moves from Platform 1. As of April 1988, suburban timetables specified an overtaking move between outbound suburban and country trains, where the 16:53 and 17:36 departures from Flinders Street to Dandenong were each scheduled to wait 3 minutes at Oakleigh, for a
Traralgon and
Warragul service, respectively. Since 1989, the station has featured over 40 plywood cut-outs on its walls and surrounding the station. These illustrate the life stories of Oakleigh residents, who were aged between 15 and 70, when the murals were unveiled in September of that year. In 2002, they underwent restoration. About half of these have since been restored, and glue can still be seen on the walls of the station building where the remainder had previously been placed. On 12 December 1995, Oakleigh was upgraded to a
premium station. When the Cranbourne line was electrified in 1995, trains that had previously terminated at Oakleigh were extended, and the passenger train stabling sidings fell into disuse. The extended goods siding that was along the north side fell out of use and was abolished around the same time, although the shell of the citybound dwarf signal at the down end remained in place until 2018. As a result, the signal panel was generally only used when the
underpass flooded, as all trains in both directions could be diverted to the north-side platform (by then renamed Platform 3). The suburban sidings were restored to service in late 2004, but were only used occasionally after that, with further periods out of service.
21st century On 3 May 2007, a Flinders Street bound Siemens train from
Pakenham derailed over a set of points at the Down end of the station. After the
Siemens trains experienced braking issues in the mid-2000s, all trains were required to be signalled through as express trains, whether or not they actually stopped at Oakleigh. This gave additional
boom barrier downtime at the level crossings between Oakleigh and Caulfield, but provided a safety margin in case of brake failure. New tracks were laid either side of the remaining platforms, and the former platform 1 alignment was converted into a side platform, with former platforms 2 and 3 renumbered to platforms 1 and 2. A new trailing crossover was provided towards Hughesdale station, and the former far down-end crossover was included in the new signalling system, all of which was worked from Dandenong. The panel was later extracted for preservation. Throughout 2018–2019, Oakleigh was upgraded and modernised. Two concourses were built, lifts were installed, and the underpass was refurbished. Two heritage-listed buildings were maintained as originally built. == Platforms and services ==