William Robert Young (born 20 January 1979) is an English singer, songwriter, and actor. He came to prominence after winning the 2002 inaugural series of the ITV talent contest Pop Idol, making him the first winner of the worldwide Idol franchise. His double A-sided debut single "Anything Is Possible" / "Evergreen" was released two weeks after the show's finale and became the fastest-selling debut single in the UK. Young also came in fifth place in World Idol performing the single "Light My Fire" written by the band the Doors.

As a teenager, Young studied politics at the University of Exeter before moving to London, where he studied musical theatre at the Arts Educational Schools in Chiswick. Young put his studies on hold in late 2001 to become a contestant on Pop Idol. After winning the competition the following year, he released his debut album From Now On (2002) which went straight to number one. Friday's Child (2003) followed and enjoyed greater success, eventually going platinum five times in the UK and spawning three top five singles. His following albums Keep On (2005), Let It Go (2008) and Echoes (2011) also went multi-platinum and 85% Proof (2015) became his fourth UK number-one album. His albums have spawned many songs that have achieved top ten positions in the UK, four of which went to the number one spot. Young has also undertaken numerous concert tours, and has accumulated multiple honours, including two Brit Awards from 12 nominations, and the estimated worldwide sale of over eight million albums. Young's net worth was estimated at £13.5 million in April 2012.

Alongside his music career, Young has acted in film, on stage and in television. For his performance in the 2013 London revival of the musical Cabaret, he was nominated for the Laurence Olivier Award for Best Actor in a Leading Role in a Musical. He has also participated in philanthropy and released books Anything is Possible (2002), On Camera, Off Duty (2004), his autobiography Funny Peculiar (2012), To be a Gay Man (2020) and The A–Z of Wellbeing (2022). In January 2022 he appeared in the third series of The Masked Singer as "Lionfish" and in May issued the compilation album 20 Years: The Greatest Hits.