The original station for Dún Laoghaire, then known as Kingstown, was situated some 0.5 miles (0.80 km) closer to Dublin at the West Pier near to or at the present-day Salthill and Monkstown railway station. That station was the southern terminus of the first railway in Ireland, the Dublin and Kingstown Railway (D&KR), which opened in 1834. For the first public timetable the station was named Kingstown but in contract documents it was at least sometimes referred to as Dunleary.

Before the D&KR had even begun to be built it became apparent that the packet boats were to use either the East Pier or the new wharf being built. Therefore, in 1833 the D&KR raised a parliamentary bill so its railway could be extended beyond the East Pier with a new station at Kingstown, then on to Dalkey. Mobilised opposition from a rival canal group and local opposition caused the Bill to fail in June 1833.

The D&KR regrouped and with lobbying presented a less ambitious bill to the site of the current station only in 1834. Thomas M. Gresham, a D&KR shareholder and main spokesperson for the opposition, being awarded a silver plate in August 1833 for the same at a personal cost of £1,200, was persuaded not to oppose the 1834 bill. Other obstacles including an agreement to cross the old part of Dunleary harbour and demolition of a Martello fortification needed an agreement with the Admiralty and Ordnance. The bill was passed in May 1834 but logistics meant Dargan began work in May 1836 finishing about a year later. The new terminus opened on 13 May 1837, the first train being a special with D&KR directors and friends.

The original station building was an apparently insufficient Station House and Parcel Office and in 1840 the D&KR resolved to replace it, hiring J. S. Mulvaney as designer. The new station building eventually cost £2,500 and was designed by Mulvaney using stone from Ballyknockan in County Wicklow in preference to granite from Dalkey quarry (which was located much closer). The platforms were finally covered in 1845 by a temporary structure costing £122 which was later extended for £300.

On 29 March 1844, the Dalkey Atmospheric Railway officially opened. The line was a branch of the existing D&KR which diverged to the south when approaching from the west with an interchange platform before the atmospheric ran as a single track eastbound into the tunnel. While through running was possible it was not used.

Grierson notes that the station build was completed in 1853 to a design by John Skipton Mulvany by Mr. Roberts doing the "masonry, carpentry, ironmongery, &c," for £1,665. L This included the station walls, while ironwork, roof, and plumbing cost £1,031 by I. & R. Mallet. The roof has since been removed. The station house above the platforms was completed in 1854. a structure in a neo-classical style, designed also by Mulvany. This was the station building until 1971 when the current arrangement was introduced. Mulvany's building became reused as a restaurant.

The Dalkey Atmospheric ceased operation in 1854. The Dublin, Wicklow and Wexford Railway exercised their rights and rebuilt the Dalkey to Kingstown section as a conventional railway at 5 ft 3 in (1,600 mm) removing height restrictions. When they ran their first train into Kingstown on 10 October 1855, the D&KR directors refused them the use of the station and the passengers were forced to return towards Dalkey, this also happening for some days afterwards. On 30 March 1856, both the D&KR and D&WR concurred with the D&KR's engineer D. B. Gibbons assessment that the rebuild under Brunel was not to the parliamentary approved specification in terms and had safety issues and it was closed for rework by William Dargan as an accident would be disastrous for both companies. Dargan converted the down line between Kingstown and Old Dun Leary harbour to dual gauge so the spoil could be dumped there. and was able to complete the re-work quickly. When the Dalkey-Bray section re-opened on 1 July 1856 the D&KR handed all its operations to the D&WR. The D&WR converted their newly acquired line to 5 ft 3 in (1,600 mm) in the next year or so enabling through running.

Carlisle Pier with its branch on the single track section just to the east of the station was created in 1859.

Although it lay on a double-track railway for over ninety years, Dún Laoghaire station had only one through platform with a bay platform facing Dublin, both on the seaward side of the station. The station lay on a short section of a single line that ran from just north of the station, to just past the junction for the branch to Carlisle Pier, which was controlled by a signal box known as the 'Hole in the Wall Box.' This arrangement created a bottleneck for intensive steam-hauled suburban services to/from Bray. It was not until 1957 that CIÉ remedied the situation by providing a second through platform. Further improvements were carried out in connection with the introduction of DART electric trains in 1984.

A replacement station entrance, with a combined ticket office and automated barriers, was built above the railway lines at street level in 1998. It was constructed with a steel framework supporting a taut sail-like canopy and with glazed panels as side features.

Also called Kingstown Harbour the station was renamed Kingstown in 1861, and renamed Dún Laoghaire in 1921. It was given the additional name "Mallin" on 10 April 1966, 50 years after the Easter Rising, when Córas Iompair Éireann renamed 15 major stations after Republican leaders. It is named in honour of Michael Mallin, a leader in the 1916 Easter Rising. although it is usually referred to simply as Dún Laoghaire.

v t e Dublin to Rosslare
Legend
Year closed Dublin–Belfast Main Line Dublin–Sligo Main Line Dublin Connolly Luas Red Line to Tallaght or Saggart R. Liffey Tara Street Dublin Pearse Grand Canal Street railway works Grand Canal Dock Grand Canal Gasworks Lansdowne Road Lansdowne Road Ballsbridge Showground Passengers 1941 Goods 1971 Serpentine Avenue Sandymount Sandymount Sydney Parade Sydney Parade Merrion Gates Merrion 1934 Booterstown Williamstown 1841 Blackrock Seapoint Salthill and Monkstown Kingstown Harbour (west pier) 1837 Dún Laoghaire Mallin Carlisle Pier 1980 Sandycove Cutting Sandycove and Glasthule Glenageary Dalkey (Atmospheric) 1854 Dalkey Killiney Hill Tunnel Obelisk Hill 1858 Killiney moved 1882 Ballybrack 1863 1882 Shankill MP 11 (to Pearse) Shanganagh Junct., to Harcourt St. 1958 MP 11 (to Harcourt St.) Woodbrook Halt 1960 County Dublin County Wicklow Bray Bray Daly Bray Cove Halt 1929 Bray Head Tunnel No.1 Bray Head Tunnel No.2 Bray Head Tunnel No.3 Bray Head Tunnel No.4 Greystones Kilcoole Newcastle 1964 Wicklow Murrough 1976 R. Vartry Wicklow Rathnew 1964 M11 motorway Glenealy 1964 Rathdrum Avoca 1964 Woodenbridge Junction 1964 Shillelagh branch line 1945 Glenart platform 1925 (private halt for Earl Carysfort) M11 motorway Arklow M11 motorway County Wicklow County Wexford Inch 1963 Gorey M11 motorway Camolin 1963 Ferns 1977 Enniscorthy R. Slaney Enniscorthy Tunnel Edermine Ferry 1963 Waterford line 1963 Macmine Junction 1963 Killurin 1963 Killurin Tunnel Ferrycarrig Tunnel Wexford (Carcur) 1872 Wexford Wexford South 1977 Felthouse Junction 1910 Limerick-Rosslare Line 2010 Rosslare Strand Kilrane 1963 Rosslare Europort

v t e South Eastern Commuter
Legend
Dublin Connolly Luas Red Line to Tallaght or Saggart Loopline Bridge Tara Street Dublin Pearse Grand Canal Dock Lansdowne Road Sandymount Sydney Parade Booterstown Blackrock Seapoint Salthill and Monkstown Dún Laoghaire Sandycove and Glasthule Glenageary Dalkey Killiney Shankill Woodbrook (planned) Bray Greystones Kilcoole Wicklow Rathdrum Arklow Gorey Dublin–Rosslare Line

v t e Dublin Area Rapid Transit
Legend
Belfast–Dublin Main Line Malahide Portmarnock Clongriffin Howth Sutton Bayside Howth Junction & Donaghmede Kilbarrack Raheny Harmonstown Killester Clontarf Road Fairview Depot River Tolka Western Commuter & Sligo Line Docklands The Royal Canal Dublin Connolly   to Dublin Heuston Luas Red Line to The Point Loopline Bridge over River Liffey Tara Street Dublin Pearse Grand Canal Dock Lansdowne Road Sandymount Sydney Parade Booterstown Blackrock Seapoint Salthill & Monkstown Dún Laoghaire Mallin Sandycove & Glasthule Glenageary Dalkey Killiney Shankill Woodbrook (under construction) Bray Daly Greystones Dublin–Rosslare Main Line

Dún Laoghaire has two through platforms and one terminal platform. Unusually, the station building is on a bridge above the platforms, in a setup similar to Leixlip Louisa Bridge railway station. The station has a ticket office, automatic ticket machines and a small coffee shop. The ticket office is open between 05:45-00:06 AM, Monday to Sunday.

From the inception of the Dublin Area Rapid Transit (DART) service in 1984, all DART services stop at Dún Laoghaire.

Dún Laoghaire is on the intercity Dublin-Rosslare and commuter Dundalk-Dublin-Arklow-Gorey routes and all trains on these routes stop here. They often run non-stop between Dun Laoghaire and Dublin Pearse, and freight and maintenance trains pass through Dún Laoghaire without stopping.

Preceding station	Iarnród Éireann			Following station
Blackrock or Dublin Pearse		InterCity Dublin-Rosslare		Bray Daly
Blackrock		Commuter Northern Commuter Peak times only		Bray Daly
		Commuter Western Commuter Peak times only
		Commuter South Eastern Commuter
Salthill & Monkstown		DART		Sandycove & Glasthule or Terminus
	Historical railways
Salthill		Dublin and Kingstown Railway		Terminus
Terminus		Dalkey Atmospheric Railway		Dalkey
Westland Row (later Dublin Pearse) Line and station open		Dublin and South Eastern Railway Dun Laoghaire boat train		Carlisle Pier Line and station closed

Directly outside the station are bus stops for Dublin Bus, Go-Ahead Ireland and other private bus operator routes, a full list of which is provided below:

There is also a taxi rank near the station on Marine Road, and a car park adjacent to the station in the harbour area.

The station is where the Killiney-Dún Laoghaire footpath "The Metals" (Ná Ráillí) ends.

It is also next to the former Dún Laoghaire Ferryport, for Stena Line services to Holyhead. This service ceased in September 2014.

• List of railway stations in Ireland

• 
  The station in 2014
• 
  Commuter train arrives from Dublin
• 
  DART 8300 Class at Dún Laoghaire Mallin station in 2008
• 
  The previous station entrance in 2007
• 
  June 1975, the footbridge was later to become the main entrance
• 
  Chartered NIR diesel train in 1982 before the new entrance
• 
  Train in cutting south of the station in 1982
• 
  The terminus platform in 2012, the other side of the wall from the through platforms
• 
  Dalkey Atmospheric Railway used what is now platform two which was previously wider
• 
  The southbound platform with the Royal Irish Yacht Club building to rear in 2014

Wikimedia Commons has media related to Dún Laoghaire railway station.

• Irish Rail Dún Laoghaire Station Website