Daniel J Davitt, who earned BA, MBA and law degrees despite never having completed grade school, died Saturday at Arlington Hospital after suffering a heart attack. He was 77.

A native of Ireland who came to this country at the age of 19, Mr. Davitt entered Antioch College on the basis of having passed an entrance examination. After graduating from that school he earned his MBA at the University of Chicago and a law degree from Georgetown University Law School.

Mr. Davitt worked as a high school teacher in Illinois before enlisting in the Army transportation corps at the time of America's entry into World War II. A captain by the war's end, he became a vocational adviser with the Veterans Administration.

Mr. Davitt also worked at various times as a management analyst for the General Services Administration and a regional director of administration for the Office of Civil Defense.

Following his retirement from government service, Mr. Davitt, taught law and accounting at several schools, including the University of Maryland, the University of Virginia, Benjamin Franklin University, Strayer College and Fts. Belvoir and Myer and the Quantico Marine Base.

A member of the District of Columbia and Virginia bars, Mr. Davitt retired from teaching in 1976.

He is survived by his wife, Elizabeth M. Davitt, of the home in Arlington; two sons, Daniel, of El Segundo, Calif., and Alan, of Derwood, Md. and two daughters, Patricia Fischer, of Alexandria, and Beth Eisenhood, of Ashland, Oregon.

He is also survived by five brothers, Patrick, of Athens, Ga; Edward, of Boca Raton, Fla; William of South Bend, Ind.; Richard, of Chicago, and James, of Union, N.J.; two sisters, Bessie Bishop, of Wilmington, Del. and Brigid Daly, of Northampton, England; and 10 grandchildren.