Down-Under, Simon returned to the theatre, where he worked as the Assistant Manager and Tech Supervisor for the Zenith Theatre in Chatswood for three years. In 1999 Lythgoe was employed by Screentime Pty. Ltd. working in Program Development. After completing one of Australia's highest rating and groundbreaking series, Popstars Season 2 and 3, Lythgoe coerced his father, Nigel Lythgoe, to license the format for Britain's ITV network. With the overwhelming success of Popstars in the UK, Nigel formed 19 Television with Simon Fuller, and the format morphed into Pop Idol. This format was later sold to the USA, known as American Idol. In 2002 Lythgoe left Australia and moved to Hollywood to help produce American Idol with his father, Nigel. Lythgoe produced some of Idol's biggest success stories including Carrie Underwood and Ruben Studard. During this period Lythgoe was also the coordinating producer for So You Think You Can Dance. After six seasons of Idol and two of SYTYCD Lythgoe was poached by Steven Spielberg and Mark Burnett as a producer for the Fox Network's On The Lot. Upon completion Lythgoe was employed as an Executive for American Idol's parent company, Fremantle Media North America. During his contract Lythgoe produced CMT's Can You Duet, NBC's Celebrity Family Feud, Fox's Osbourne Reloaded and advised on America's Got Talent, I've Got Your Number and Let's Make A Deal. In 2010 Lythgoe left Fremantle Media N.A. and setup his own company, Legacy Productions. The production company established development deals with a number of development Executive Producers in Hollywood. In the first quarter of 2011, Legacy Productions, with Simon as the Showrunner, produced "CMTs Next Superstar" for Country Music Television, part of the MTV Networks. The series was commissioned for a second season, but was later cancelled for creative and budgetary reasons. In 2012 Simon developed, directed and was the Showrunner on "A Chance to Dance" for Ovation and "Opening Act" for E! Network. More recently Lythgoe was the Co-Executive Producer for a CBS pilot, "The Spotlight" and an untitled social experiment series for ABC Family. In 2015 Lythgoe returned to Sydney, Australia to help produce "Aladdin" at the State Theatre for Bonnie Lythgoe Productions before returning to television in Los Angeles. He then produced a wife swap type pilot with the production company, 44Blue and the Disney cable network Freeform entitled "Take My Kids". Simon continued to produce for the same network a