Henry Francis de Court, 59, an electronics with the National Security Agency since the mid-1950s who was active in church and volunteer organizations, died Sunday at North Arundel Hospital in Glen Burnie after a stroke.

He came to Washington as a civilian empolye of the Defense Department in 1952.

Mr. de Court served with the Navy in the Atlantic and the Pacific during World War II. He served in Korean waters during the conflict there. He retired from the Navy reserves in 1979 with the rank of commander.

Mr. de Court was a resident of Bethesda, where he was a member of the Bradley Hills Presbyterian Church. He had served several terms on the church court session and was a session clerk and ruling elder.

He had been a member of the troop committee of Boy Scout Troop No. 923 in Bethesda for the past 13 years. He also had been chairman of the National Scholarship Committee of the Foundation for Amateur Radio.

Mr. de Court was born in Orange, Tex., and was reared in Chicago and Savannah, G. He earned a bachelor's and a master's degree in engineering at the Georgia Institute of Technology. He was a 1969 graduate of the National War College.

Survivors include his wife, the former Dorothy Loving; a daughter Amelia; and a son Charles, all of Bethesda.

The family suggests that expressions of sympathy be in the form of contributions to the Music Fund at Bradley Hills Presbyterian Church, 6601 Bradley Blvd., Bethesda, Md. 20034. CAPTION: