J. Terry Hirst, 93, the chairman of the board of the J. T. Hirst Co. Inc., a lumber firm in Leesburg, and a former member of the Loudoun County Board of Supervisors and the county school board, died Tuesday at Loudoun Memorial Hospital after a stroke.

Mr. Hirst was born in Purcellville, Va., and lived there all of his life.

He graduated from the Virginia Military Institute in 1908 with a degree in civil engineering and took graduate courses at Cornell University. When he completed his education, he joined the E. T. Hirst lumber company, which was run by an uncle, in Purcellville.

He then worked on the construction of railroads in Idaho, British Columbia and Florida, where his job was on the Flagler Railroad through the Everglades to Key West.

During World War I, Mr. Hirst was a first lieutenant in the Army Chemical Corps and served in France with the 29th Division.

After the war, he returned to Purcellville and engaged in the pulp paper business. In 1927, he bought the Norris Lumber Co. in Leesburg. This became the J. T. Hirst Co. Inc. Mr. Hirst went into partial retirement in the late 1960s, but remained as chairman of the board until his death.

Mr. Hirst served on the Loudoun County Board of Supervisors for 22 years. He also served on the county school board and the Purcellville Town Council. He was a founder of the Purcellville Volunteer Fire Department and its first chief. He also was a founder of the Leesburg Rotary Club. He was a member of the American Legion, the Veterans of Foreign Wars and the Masons.

His wife, Katherine Fox Hirst, died in 1966.

Survivors include two children, Mrs. Andrew D. Bogle of Purcellville, and Julian F. Hirst of Norfolk, and six grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the VMI Foundation Inc., Lexington, Va., 24450, or to the Katherine F. Hirst Memorial Fund, St. Peter's Church, Purcellville, Va., 22132.