Nellie M. Cahill, 88, a retired owner and operator of Cahill's Restaurant in Washington and an area resident for 60 years, died of a stroke Sunday at her home in Arlington.

Born in Bally Haunis, County Mayo, Ireland, Mrs. Cahill came to the United States at age 16 and settled in Boston. She lived in Boston and New York, working as a governess, until 1921, when she married John Cahill, a native of Ireland and a resident of Washington.

In 1933, the couple established Cahill's Restaurant in the DuPont Circle area. Together they operated the business, where Mrs. Cahill was known to her patrons as "Mrs. C" or "Miss Nellie," until Mr. Cahill's death in 1960. Mrs. Cahill then supervised the restaurant's operation until 1973, when she retired and moved to Arlington to live with a daughter, Patricia A. Sullivan.

A former member of the parish of St. Matthew's Cathedral in Washington, Mrs. Cahill was a member of the parish of St. Agnes Catholic Church in Arlington at the time of her death.

Besides Mrs. Sullivan, Mrs. Cahill's survivors include another daughter, Frances Boyce of South Bend, Ind.; three sons, Robert V., of Palos Verdes, Calif., and Thomas M. and John M., of Falls Church; two sisters, Nora McHale of Arlington and Mary Eagney of Bethesda; 23 grandchildren and two great-grandchildren.

The family suggests that expressions of sympathy be in the form of contributions in Mrs. Cahill's name to a charity of one's choice.