The assault happened at a house in Park Na Sillogue Court at about 4pm. Emergency services attended and the victim was pronounced dead at the scene.
A man in his 40s has been arrested and taken to Bray Garda station. Gardaí are not looking for anyone else in relation to this incident.
The scene is being preserved and a Garda technical examination is being carried out.
The State Pathologist has been notified and gardaí say a postmortem will be conducted at a later date.
Gardaí have appealed for anyone with information, particularly those who were in the Park Na Sillogue area on Friday afternoon between 3pm and 4pm, to come forward.
Anyone with any information can contact Bray Garda station on 01 666 5300, the Garda Confidential Line on 1800 666 111 or any Garda station.
The National Women’s Council of Ireland said on Friday evening: “Our thoughts and solidarity are with this woman and her family.
“If you need them this Christmas, the Women’s Aid 24-Hour Freephone Helpline is 1800 341 900.”