Johnny Knoxville. Writer: Jackass: Bad Grandpa. Johnny Knoxville was born on 11 March 1971 in Knoxville, Tennessee, USA. He is a writer and producer, known for Jackass: Bad Grandpa (2013), Teenage Mutant Ninja Turtles (2014) and Ein Duke kommt selten allein (2005). He has been married to Naomi Nelson since 24 September 2010. They have two children. He was previously married to Melanie Lynn Cates.