Arthur P. Gill, 78, active for many years in veterans affairs here, died Monday in Mary Washington Hospital in Fredericksburg, Va. He had suffered from leukemia.

Born in Brooklyn, Mr. Gill came to Washington as a child with his family. During World War I, he served with the U.S. Navy and saw duty in Ireland and England. After the war, he was in Russia with the Hoover relief administration.

Mr. Gill started his career as a civilian government employe in 1941 in the army adjutant general's office, where he served during World War II.

He later worked for the Department of Health, Education, and Welfare and retired from its radiological health bureau in Rockville in 1967. He moved from Washington to Colonial Beach, Va., five years ago.

Mr. Gill was a past commanader of the Irish War Veterans of the District of Columbia and Victory Post No. 4 of the American Legion in Washington. He was a life member of the West-moreland County Post No. 148 of the American Legion.

He is survived by his wife, Eva, of the home; four sons, Arthur P. Jr., of Colonial Beach, Michael E. and Timothy J., both of Fredericksburg, and Daniel P., of Hyattsville; a daughter, Susan J. Machalek, of New York City; a brother, Frank M., of Greenbelt, and four grandchildren.