Dale C. Dillon, 78, a retired Washington lawyer, died Tuesday in St. Petersburg Fla., where he had lived for the last six years.

He retired as a senior partner with the firm of Todd, Dillon and Sullivan in the mix-1960s. He had been with the firm, which specialized in transportation law, for 25 years. Prior to that, Mr. Dillon had been an attorney - examiner with the Interstate Commerce Commission.

Born in Coffeyville, Kan., he interrupted his studies at the University of Kansas to serve with the 35th Division of the Army Engineer Corps in World War I. He was wounded in the Meuse - Argonne campaign in France.

Mr. Dillon returned on the University of Kansas after the war and earned a law degree. He was a lawyer with the Armour meat packing company in Chicago before coming here in the early 1930s.

A former resident of Arlington, he had been a deacon at Columbia Baptist Church in Falls Church and a member of the Veterans of Foreign Wars, the American Legion and Masonic Kempre Lodge in Falls Church.

He is survived by his wife, Viola May, of the home in St. Petersburg; a daughter, Joanne Lichty, of Arlington; a son, Robert, of the American Embassy in Kuala Lumpur, Malaysia, eight grandchildren and two great-grandchildren.