Dennis Walker Ladd, 72, a retired personnel official in the Department of the Army who was active in civic and service groups, died of cancer March 14 at his home in Vienna.

Mr. Ladd was born in Richmond and reared in Arlington. He graduated from Washington-Lee High School and earned a law degree at Southeastern University. He served in the Army in world War II.

In the 1930s, he went to work for the National Archives. He later joined the old War Department, which became the Departmnt of the Army. He retired in 1970.

He was a past commander of American Legion Post 180 in Vienna, a chef de gare of Voiture 934 of the 40 and 8 society of the Legion, a past president of Chapter 1116 of the National Association of Retired Federal Employees, and a member of the Virginia Bar Association, the Fairfax Commission on Aging and the Mayor's Advisory Committee of Vienna.

Survivors include his wife, Evelyn T., of Vienna; two children, Dennis W., of Honolulu, and Judith Ellen, of Arlington; two brothers, Graham, of Saint Davids Church, Va., and Hugh, of Forestville, and a sister, Marjorie Newlon of Lake-of-the-Woods, Va.