Irish Government sources have named the women as Marion Elizabeth Graham and Kathy Dinsmore, both from the Newry area of County Down.
The middle-aged women were murdered late last night in the city of Izmir, about 75 miles from the resort of Kusadasi in the west of the country.
A 17-year-old Turkish youth, understood to be the boyfriend of a daughter of one of the women, has been arrested. It is believed he has confessed to the attack.
Irish diplomats are liaising with relatives of the two women.
A spokesman for the Department of Foreign Affairs in Dublin confirmed consular staff are trying to track down family members. “We are providing consular assistance through the embassy in Ankara,” the spokesman said.
It is understood one of the women owns a property in the Kusadasi area and they had travelled into Izmir, where they were attacked.
South Down MP Margaret Ritchie said she was shocked by the deaths and offered her sympathy to the bereaved families.
“My thoughts are with those involved in this terrible incident,” she said.
“And also with their families, who never got the chance to say goodbye to their loved ones.
“I think all the people of South Down will be saddened by this news.”