John Michael "Ozzy" Osbourne (born 3 December 1948) is an English singer, songwriter, and media personality. He rose to prominence during the 1970s as the lead singer of the heavy metal band Black Sabbath, during which period he adopted the nickname "Prince of Darkness".

Osbourne became a founding member of Black Sabbath in 1968, providing lead vocals from their self-titled debut album in 1970 to Never Say Die! in 1978. The band was highly influential in the development of heavy metal music, in particular their critically acclaimed releases Paranoid, Master of Reality, and Sabbath Bloody Sabbath. Osbourne was fired from Black Sabbath in 1979 due to alcohol and drug problems. He then began a successful solo career with Blizzard of Ozz in 1980 and has released 13 studio albums, the first seven of which received multi-platinum certifications in the US. He has since reunited with Black Sabbath on several occasions. He rejoined in 1997 and helped record the group's final studio album, 13 (2013), before they embarked on a farewell tour that ended with a 2017 performance in their native Birmingham. His longevity and success have earned him the informal title of the "Godfather of Metal".

Osbourne has sold over 100 million albums, including his solo work and Black Sabbath releases. He was inducted into the Rock and Roll Hall of Fame as a member of Black Sabbath in 2006 and as a solo artist in 2024. He was also inducted into the UK Music Hall of Fame both solo and with Black Sabbath in 2005. He has been honoured with stars on the Hollywood Walk of Fame and Birmingham Walk of Stars. At the 2014 MTV Europe Music Awards, he received the Global Icon Award. In 2015, he received the Ivor Novello Award for Lifetime Achievement from the British Academy of Songwriters, Composers and Authors.

In the early 2000s, Osbourne became a reality television star when he appeared in the MTV reality show The Osbournes alongside his wife and manager Sharon and two of their children, Kelly and Jack. He co-stars with Jack and Kelly in the television series Ozzy & Jack's World Detour.