Gregory C. Zipadelli, nicknamed "Zippy", (born April 21, 1967) is an American crew chief in NASCAR. He is currently the competition director at Stewart-Haas Racing. Zipadelli is most notable for being the crew chief of the #20 car for Joe Gibbs Racing drivers Tony Stewart and Joey Logano from 1999 to 2011. He has won 34 races and two championships in 2002 and 2005 as a crew chief.