The borough was formed under the Local Government (Dublin) Act 1930 from the urban districts of Blackrock, Dalkey, Dún Laoghaire, and Killiney and Ballybrack.

[1] Whereas most Irish boroughs had the limited autonomy of an urban district, Dún Laoghaire had greater powers and was for many purposes practically a county borough independent of Dublin County Council.

The corporation headquarters was in Dún Laoghaire Town Hall.

Dún Laoghaire was one of seven (non-county) boroughs and urban districts with its own Vocational Education Committee (VEC).

Under the same provisions, the borough of Dún Laoghaire also ceased to exist.