Born in Berwickshire, Scotland, Gillie moved to the United States with his parents, who settled in Kankakee, Illinois, in 1882 and in Fort Wayne, Indiana, in 1884. He attended the public schools, International Business College, Fort Wayne, Indiana, in 1898, and Purdue University, Lafayette, Indiana from 1899 to 1901. He was graduated from Ohio State University at Columbus in 1907 as doctor of veterinary surgery. Meat and dairy inspector of Allen County, Indiana from 1908 to 1914. Began the practice of veterinary medicine in Fort Wayne, Indiana, in 1914. Sheriff of Allen County 1917-1920 from 1929 to 1930, and 1935-1937.
Gillie was elected as a Republican to the Seventy-sixth and to the four succeeding Congresses (January 3, 1939 - January 3, 1949). He was an unsuccessful candidate for reelection in 1948 to the Eighty-first Congress. He engaged in agricultural pursuits. Jury commissioner for the Federal courts for the northern district of Indiana. Resident of Fort Wayne, Indiana, until his death there on July 3, 1963. He was interred in Lindenwood Cemetery.
This article incorporates public domain material from the Biographical Directory of the United States Congress website http://bioguide.congress.gov.