Garret "Jacknife" Lee is an Irish music producer and mixer. He has worked with a variety of artists, including the Cars, U2, R.E.M., the Killers, Robbie Williams, Snow Patrol, Bloc Party, Two Door Cinema Club, AFI, the Hives, Weezer, One Direction, Silversun Pickups, Editors, Modest Mouse, Lonnie Holley and Taylor Swift.