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., Snow Patrol, Bloc Party, AFI, The Hives, Weezer, Vega4 and Editors.

Lee started as a guitarist for the punk band Compulsion, then pursued a solo career in the field of electronica after the band's break-up. His first solo work, the EP A Dog Named Snuggles, was released under the name Jacknife Lee in 1998 by Pussyfoot Records, a label founded by Howie B.

Lee released his first album Muy rico in 1998. His second album Punk Rock High Roller was released in 2001 by Palm Pictures. To Hell With You I'll Make My Own People was recorded as Jack Planck for the One Little Indian label. Jacknife Lee released his self titled third solo album in 2007.

Jacknife Lee has also remixed a variety of artists' work including a version of Run-DMC's "It's Tricky 2003", The Future Sound of London's "The Mello Hippo Disco Show" and versions of U2's "Vertigo" which was limited released onto 7", 10" and 12" vinyl, Christina Aguilera, TLC, Pink, Blur, Radiohead, Missy Elliott, Busta Rhymes, Eminem, The Raveonettes, Dirty Vegas, Kraftwerk, New Order, Aqualung and Kasabian. In 2008 he produced R.E.M.'s Accelerate, Bloc Party's Intimacy and Hadouken!. Crystal Castles worked with him for a few weeks in 2009 for their second album, after which he worked with LostAlone. In 2010 he produced R.E.M.'s latest album Collapse into Now, which was released in 2011.