The Ultimate Sin is the fourth studio album by English heavy metal singer Ozzy Osbourne. It was released on 24 January 1986, and was remastered and re-issued on CD on 22 August 1995. It is the second and last of Osbourne's albums to feature lead guitarist Jake E. Lee, the first to feature drummer Randy Castillo, and the only album to feature bassist Phil Soussan, who co-wrote the album's hit single "Shot in the Dark".

John Michael "Ozzy" Osbourne is an English musician 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".