Dún LaoghaireâÂÂRathdown () is a county in Ireland. It is in the province of Leinster and the Eastern and Midland Region. It is one of three successor counties to County Dublin, which was disestablished in 1994. It is named after the former borough of Dún Laoghaire and the barony of Rathdown. Dún LaoghaireâÂÂRathdown County Council is the local authority for the county. The population of the county was 233,860 at the time of the 2022 census.
Dún LaoghaireâÂÂRathdown is bordered to the east by the Irish Sea, to the north by the city of Dublin, to the west by the county of South Dublin, and to the south by County Wicklow. With the city of Dublin, Fingal and South Dublin, it is one of four local government areas in the old County Dublin. Located to the south-east of the capital city of Dublin, the county town of Dún Laoghaire–Rathdown is Dún Laoghaire. Since 2015, the county is part of the Eastern and Midland Region. University College Dublin and Dún Laoghaire Institute of Art, Design and Technology are located in the county.
In 1986, the administrative county of Dublin was divided into three "electoral counties": Dún LaoghaireâÂÂRathdown, DublinâÂÂFingal, and DublinâÂÂBelgard. The city has been administered separately from County Dublin since 1548. An "area committee" for the electoral county was formed within Dublin County Council under the Local Government Act 1991,
On 1 January 1994, County Dublin and the Borough of Dún Laoghaire were abolished and the three electoral counties became the administrative counties of Dún LaoghaireâÂÂRathdown, Fingal, and South Dublin respectively. Under the related act, the Local Government (Dublin) Act, 1993, Dún Laoghaire-Rathdown County Council (together with South Dublin County Council and Fingal County Council) became one of the three "successor" councils to Dublin County Council.
The Dún LaoghaireâÂÂRathdown Council area comprises the former Borough of Dún Laoghaire and the south-eastern part of the former County Dublin. Additionally, the powers of the former Deansgrange Joint Burial Board were subsumed into the new authority. From 2002, all "administrative counties" in Ireland were redesignated as "counties". The three counties together with Dublin city constitute the traditional County Dublin.
The coastal town of Dún Laoghaire (called Dunleary until 1821 and then Kingstown until 1920) gave its name to the larger borough of Dún Laoghaire established in 1930. Rathdown was the south-easternmost barony in County Dublin, named after Rathdown Castle. When County Wicklow was created south of County Dublin in 1606, half of Rathdown was transferred to Wicklow, including Rathdown Castle, now a ruin. From the 1840s, the poor law union (PLU) of Rathdown covered all of the Wicklow barony and most of the Dublin barony, with part of Uppercross. From the Dublin and Wicklow sections of the PLU, the Local Government (Ireland) Act 1898 created rural districts respectively named Rathdown No. 1 and Rathdown No. 2, abolished in 1930 and 1925. Rathdown PLU survived as Rathdown Public Assistance District until 1960. Dún Laoghaire and Rathdown was a Dáil constituency created by the Electoral (Amendment) Act 1947 coterminous with the former Rathdown No. 1 rural district.
The name "Dún LaoghaireâÂÂRathdown" was given to the electoral county created in 1985. Before its establishment as an administrative county, possible alternative names before deciding to retain "Dún LaoghaireâÂÂRathdown". The Local Government (Dublin) Act 1993 named it "Dun LaoghaireâÂÂRathdown" in English, omitting the on the "u" of "Dun", and in Irish. The 1993 act empowered Dún LaoghaireâÂÂRathdown County Council (DLRCC) to apply to change the county's name, but this was not invoked.
The spelling in English as "Dun LaoghaireâÂÂRathdown", without the , is used in the list of counties in the Local Government Act 2001 (and as amended by the Local Government Reform Act 2014). However, in the Placenames Database of Ireland and the ministerial order under the Official Languages Act 2003, the name of the county in English is "Dún LaoghaireâÂÂRathdown". This is followed by the County Council, with the used in English.
The placenames order also distinguishes between the use of "County" as a prefix for the traditional counties, but not in the case of "Dún LaoghaireâÂÂRathdown" and other counties listed as "administrative counties".
Dún LaoghaireâÂÂRathdown County Council is the local authority for the county. There are six local electoral areas (LEAs) for the county which return a total of 40 councillors as follows: Blackrock (6), Dundrum (7), Dún Laoghaire (7), GlencullenâÂÂSandyford (7), KillineyâÂÂShankill (7), and Stillorgan (6).
For elections to Dáil ÃÂireann, the county is split between the Dáil constituencies of Dún Laoghaire (4 TDs) and Dublin Rathdown (3 TDs), with the division generally running along the N11. These constituencies currently have three Fine Gael TDs, two Green Party TDs, one Fianna Fáil TD and one People Before ProfitâÂÂSolidarity TD.
It is part of the 4-seat Dublin constituency in European Parliament elections.
The motto on the insignia of the County Council reads, , Irish for "From Harbour to Mountain". The crown in the device is that of Lóegaire mac Néill, a legendary 5th-century High King of Ireland and the eponymous Laoghaire of "Dún Laoghaire".
The Dublin Area Rapid Transit (DART) system runs through the eastern coast of the county and connects to Dublin city centre to the north as well as other points north and south on the Iarnród ÃÂireann railway system, with connections to Intercity and commuter trains. The Luas Green Line runs through the centre of the county.
There is a medium-sized harbour at Dún Laoghaire, with now discontinued ferry crossings to and from Holyhead in North Wales; this was a popular route for tourists travelling across the Irish Sea from Britain. This service was suspended indefinitely in September 2014.