Onstead began working in his father's grocery chain in Texas, eventually rising to chairman, president and CEO. He oversaw the sale of that chain to Safeway in the 1990s and went to work for a division of Safeway. He was CEO at Garden Ridge before joining the Bi-Lo board of directors in 2008 as interim CEO. He became chairman the next year and in 2012 was named CEO of Bi-Lo Holdings.