Ralph Horton Jr., 61, a former Defense Department official and a campaign aide for both John and Robert Kennedy, died Saturday in a fire at his home in Virginia Beach.

Born in New York City, he graduated from the Choate School in Wallingford, Conn., and earned a bachelor's degree from Princeton. One of his roommates at Choate and, briefly, at Princeton, was John F.Kennedy. The future President of the United States attended Princeton only briefly and then went on to Harvard.

Mr.Horton served in the North African and Italian campaigns in World War II. After holding a number of jobs in New York and Texas, he joined John Kennedy's presidential campaign in 1960.

He was active in the campaigns of Robert Kennedy, both for the U.S. Senate in 1964 and the presidential race in 1968.

He had lived in Virginia Beach for the past eight years where he was director of eduction and training for the Southeast Tidewater Opportunity Project (STOP), a federally funded organization based in Norfolk that provides job training for the economically disadvantaged.

Mr.Horton was past-president of the New Frontier Club in Washington and was a member of the New York Athletic Club.

He was a member of the Catholic Church of the Ascension in Virginia Beach, where he had been past-chairman of the parish council.

He is survived by his wife, Rosina, and sons Mark and John, all of the home, and sons, Dr. Daniel, of Hartford, Conn. and Ralph III, of Syracuse, N.Y., and a brother, Theodore T., of Hartford, Conn.

The family suggests that expressions of sympathy be in the form of contributions to the building fund of the Church of the Ascension in Virginia Beach.