Dixon was born in Shelby, North Carolina, the son of Thomas Jeremiah Frederick Dixon II and Amanda Elvira McAfee, daughter of a planter and slave-owner from York County, South Carolina. He was one of eight children, of whom five survived to adulthood. His elder brother, preacher Amzi Clarence Dixon, helped to edit "The Fundamentals", a series of articles (and later volumes) influential in fundamentalist Christianity. "He won international acclaim as one of the greatest ministers of his day." His younger brother Frank Dixon was also a preacher and lecturer. His sister, Elizabeth Delia Dixon-Carroll, became a pioneer woman physician in North Carolina and was the doctor for many years at Meredith College in Raleigh, N.C.