David LeMar Titus, 65, a senior operations officer with the Central Intelligence Agency for about 20 years before retiring in the early 1970s, died of renal failure Aug. 4 at Georgetown University Hospital. He had cancer.

Mr. Titus was a native of South Charleston, Ohio. He attended Arizona State and Ohio universities. While serving with the old Army Air Forces during World War II, he was a liaison officer with Britain's Royal Air Force in England. He was a writer with Collier's magazine and several English financial publications before returning to this country in 1950.

He moved to Washington in 1950 and joined the CIA a year later.

Mr. Titus was a resident of Washington. He was a member of the board of directors of the Foreign Student Service Council of Greater Washington and a member of the City Tavern Association, the Kenwood Golf & Country Club in Bethesda and the Reform Club of London.

His first wife, Ana McMurtry Titus, died in 1974.

Survivors include his wife, Faith Donaldson Titus, of Washington; three children by his first marriage, David Titus of Venice, Fla., and Mary A. Titus and Mrs. Thomas Scroggie, both of Falls Church; three stepchildren, Lawrence d'Oench of Columbus, Ohio, Allan Ackerman of Arlington, Mass., and Marjory Dixon of Houston; a sister, Mrs. Oliver Weber of Cleveland, and five grandchildren.