Gregory Jack Biffle, nicknamed "the Biff", (born December 23, 1969) is an American semi-retired professional stock car racing driver.
After racing in the NASCAR Winter Heat Series in the mid-1990s, he was recommended to Jack Roush by former racer and announcer Benny Parsons. With Roush Racing, he was the 1998 NASCAR Craftsman Truck Series Rookie of the Year. He won the 2000 Craftsman Truck championship. He reprised this progression in the NASCAR Busch Series, winning the 2001 Rookie of the Year, immediately followed by winning the 2002 championship. Biffle drove in the NASCAR Sprint Cup Series for Roush from 2003 until 2016, winning 19 races in the No. 16 Ford.
Biffle, who began his NASCAR career in 1995, is the first of only three drivers that have won a championship in both the Busch Series and the Craftsman Truck Series, and the sixth of only thirty-six drivers to win a race in each of NASCAR's three national series. Biffle returned to NASCAR in 2019 when he ran the 2019 SpeedyCash.com 400 for Kyle Busch Motorsports, which he won. He last competed part-time in the NASCAR Cup Series, driving the No. 44 Chevrolet Camaro ZL1 for NY Racing Team.