Gary Paul Gillum was born June 12, 1944 in Indianapolis, Indiana, to Paul and Ruth Gillum. Because his father was in the U.S. Air Force, Gillum grew up in several locations throughout the United States, as well as living in Germany from 1953 to 1956. Having been raised in the Lutheran Church, Gillum formed an affinity early on with the Lutheran ministry and music. This led him to study at Concordia College, where he recieved a Bachelor of Pre-ministerial Studies and Classics degree, with a minor in sacred choral music, in 1968. He joined the Church of Jesus Christ of Latter-day Saints one year later and married Lyn Ann Ruhland on July 12, 1969. They moved to Provo, Utah, where Gary obtained a Master of Library Science degree from Brigham Young University (BYU) in 1971 and was then hired to be the Foreign Languages bibliographer. Gary and Lyn's two children, Grant and Adina, were born 1971 and 1973, respectively. Lyn, however, died in 1977 of lymphoma. Gary eventually married Elizabeth Bayliss and they had a daughter, Annalyn, in 1979. In 1986 Gary was tragically widowed once again after Elizabeth died of cancer. Gary became the Ancient Studies and Philosophy librarian in 1980, a position he would keep until his retirement. While at BYU Gillum worked closely with Hugh Nibley, eventually publishing a Nibley quote book as well as teaching a class on Nibley. He has sung with the fort Wayne Philharmonic Choir, the Indianapolis Symphonic Choir, the BYU Men's Chorus, the Payson Civic Chorale, and the Utah Baroque Ensemble. He has been married since 1987 to Signe Hale, and the couple served a mission to Anaheim, California, from 2009 to 2010.