Glenageary (Irish: Gleann na gCaorach, meaning "Glen of the Sheep") is an area in the suburbs of Dún Laoghaire–Rathdown, Ireland. While there is no officially defined boundary, it is surrounded by the areas of Dalkey, Dún Laoghaire, Glasthule and Johnstown. The Church of Ireland does have a defined boundary for the Parish of Glenageary.
On early 20th century maps Glenageary and Sallynoggin are considered to be the same place and it was not until the building of local authority houses in the late 1940s and 1950s in the townlands of Honeypark and Thomastown by Dún Laoghaire Borough Corporation that a clear distinction between Sallynoggin and Glenageary was created.
The Roman Catholic Parish of Glenageary covers all of Upper Glenageary Road, Bellevue, Avondale, Adelaide and Silchester Roads.
Glenageary is a quiet, affluent suburb and consists mostly of private dwellings with shops and some amenities in places.
Until the late 1940s, Glenageary, like much of the south County Dublin, consisted mostly of large manor estates - each comprising a large house, some woodland and cultivated or landscaped fields. Since then it has been extensively redeveloped. Most of the original manors have been demolished and low density housing developments built.
- Sinéad O'Connor and her novelist brother Joseph O'Connor spent some of their early lives in Glenageary
- The former Church of Ireland Archdeacon of Dublin, was rector of St Pauls, Glenageary for twenty-four years and a local resident. Previous rectors have also been similarly promoted – to bishop; John Duggan (Tuam) and Noel Willoughby (Cashel & Ossory) and to archbishop; Dr. Walton Empey (Dublin); Jamie Noble (Castlebarr)
- Niall Connolly, one of the Colombia Three spent his childhood in Glenageary
- Colm Ó Cíosóig, musician and drummer of My Bloody Valentine, is from Glenageary
- John Dowse was an Irish-born British Army medical officer in World Wars I and II.
- A 17-year-old resident, Raonaid Murray, was murdered on Silchester Road on 4 September 1999 near her home.
The area is served by Dublin Bus, including routes 7, 7a, 45a, 59, and 111 although these vary in frequency and service periods. Glenageary has its own railway station which is served by Iarnród Éireann's DART that provides a service between Greystones to the south, and Howth and Malahide to the north. Glenageary railway station opened on 1 November 1867.
- "Glenageary station" (PDF). Railscot – Irish Railways. Retrieved 2007-09-02.