The woman was discovered at a property at Kincora Court in Dublin 3 on Sunday evening with fatal injuries, according to a Garda statement.
Her body remained at the scene overnight, which has been sealed off by gardaí.
A man in his 60s was arrested at the scene and is currently being detained under Section 4 of the Criminal Justice Act, 1984 in Clontarf Garda station.
The relationship between the man and the woman is not known.
It is understood gardaí are not looking for anyone else in connection with the incident.
The scene was preserved and the State Pathologist’s Office was notified.
A Garda spokeswoman said investigations are ongoing.
