Tallaght ( Tamhlacht in Irish), after Dublin and Cork, is the third greater agglomeration in Ireland.

Located at 13 kilometers in Dublin south-west, with the foot of the mountains of Wicklow, it was one of the monastic centers most important of medieval Ireland. The area of Tallaght is actually composed of a whole of rural and urban/suburban sectors. One says Tallaght commonly that it is a town of formless residences which were built at the end of the years 1960. The village, dating at least from the 17th century, occupies a significant historical site by the religious value of the site and the new center town which was started towards the end of the year 1980 made of Tallaght the administrative capital of Dublin-South.

Tallaght extends to the east from Templeogue and the west from Saggart, the south of Knocklyon, and finally to the north of Clondalkin and Walkinstown. Because of its important demography, there were calls to give him the statute of city however, Tallaght is still considered as an element of the Grand Dublin.