Margaret E. Gerrity, 65, the widow of Air Force Gen. Thomas P. Gerrity, died of a coronary occlusion Wednesday at Chevy Chase House in Washington.

Mrs. Gerrity was born in Birmingham and grew up in Little Rock, Ark., where she lived until she married the future Gen. Gerrity and accompanied him to various military posts in the United States.

Gen. Gerrity was stationed in Washington from 1961 to 1967, when he was transferred to Wright-Patterson Air Force Base in Dayton, Ohio. Following his death early in 1968, Mrs. Gerrity returned to this area and made her home in Alexandria. She lived there until about eight months ago, when she moved to Chevy Chase House, a retirement home.

She had been a member of the Arlington Committee, a group of military wives who assist families who are attending funerals at Arlington National Cemetery. She also had been active in the Red Cross and other organizations.

Survivors include a daughter, Rita Morrow of Hong Kong; a son, Dr. Thomas Gerrity of Boston; a sister, Madelaine Kroner of Schererville, Ind., and three grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Pediatric Endocrinology Research Fund, University of Chicago Hospital, Chicago.