Ozzfest was an annual music festival tour of the United States and sometimes Europe and later Japan, featuring performances by many heavy metal and hard rock musical groups. It was founded by Sharon Osbourne and her husband Ozzy Osbourne, both of whom also organised each yearly tour with their son Jack Osbourne, and was held almost annually between 1996 and 2018. The Ozzfest tour featured bands of a variety of genres within heavy metal and hard rock, including alternative metal, thrash metal, industrial metal, metalcore, hardcore punk, deathcore, nu metal, death metal, post-hardcore, gothic metal and black metal. Ozzy Osbourne and Black Sabbath played the tour several times over the years.

Sharon Rachel Osbourne is a British television personality, music manager, and author. She is married to heavy metal singer Ozzy Osbourne and came to prominence while appearing on The Osbournes (2002–2005), a reality television show that aired on MTV, which followed her family's daily life. Osbourne later became a judge on television talent competition shows, including The X Factor and America's Got Talent (2007–2012).