Helen Cecilia Tansill, 82, a former federal government employe and resident of Washington for more than 50 years, died of a heart attack Wednesday in Tucson, Ariz.

Her last position, from which she retired 10 years ago, was with the House Post Office and Civil Service COmmittee. She then moved to Tucson to live with a daughter, Mrs. Frank Sharkey.

Mrs. Tansill was born in Danville, Ohio. She moved to Washington while still in her teens and in 1915 married Charles C. Tansill, a professor of American history whose conservtive views later stirred some controversy.

Around the years of World War I. Mrs. Tansill was a private secretary to Rep. William Ashbrook (D-Ohio). Later, while her husband was a professor at American University, she was his research assistant.

They lived in New York from 1939 to 1944, while he taught at Fordham University. They then returned to Washington and Mrs. Tansill processed the sale of government bonds for the Treasury Department while her husband taught at Georgetown University.

After his death in 1964, she went to work for the House committee. She has been a member of St. Anthony's Catholic Church in Washington.

In addition to Mrs. Sharky, she is survived by two other daughters, Mrs. Leon Morton, of Tuscon, and Mrs. Jack B. C. Purcell, of Chatworth, Calif: two sons, Dr. William R., of University Park, and Charles B., of LaPlata Md: a brother, James D. Parker, of Kensington: a sister, Mrs. Tom Hickey, of Falmougth, Mass., and 16 grandchildren.