Mildred Eddy Dunn, 88, a Red Cross volunteer in two world wars and a resident of Washington since the early 1920s, died at Georgetown University Hospital on Sunday following a heart attack.

Mrs. Dunn was born in New York City and grew up there, During World War I, she was a volunteer with the Red Cross in Halifax, Nova Scotia, and later in France. During World War II, she was head of the Red Cross Gray Ladies at Red Cross national headquarters in Washington.

She had come to Washington following her marriage to William McKee Dunn, an Army officer who retired as a brigadier general and who died in 1973. The Dunns also had a house in Hot Springs, Va., and Mrs. Dunn had divided her time between Washington and Hot Srpings in recent years.

She was a trustee of the Potomac School in MclLean for many years. She had been a member of the board of St. John's Orphanage and a member of the Washington committee of the American Field Service.

She was a member of the Sulgrave Club in Washington and the Colony Club in New York City.

Survivors include four daughters, Mrs. Orme Wilson Jr. and Mrs. William B. Poland Jr., both of Washington, Mrs. Dunn Burnett of Cambridge, Mass., and Mrs. Louis A. Cox of McLean, and 11 grandchildren.