Dorothy A. Kennedy, who was a grand master at bridge, died Tuesday of heart disease at home in Fernandina Beach, Fla., where she and her husband spent the winters. She was 80 and lived on Scarlett Drive in Towson.

In addition to her husband, survivors include three sons, John F. Kennedy III of Washington's Crossing, Pa., Richard A. Kennedy of Crofton and Robert L. Crofton of Baltimore; a daughter, Barbara Kennedy Yurick of Towson; and seven grandchildren.