Who was the original lead singer of the band Black Sabbath?

The original lead singer of Black Sabbath was Ozzy Osbourne.

Osbourne was part of Black Sabbath's founding lineup, alongside guitarist Tony Iommi, bassist Geezer Butler, and drummer Bill Ward. The group formed in Birmingham, England, in 1968, initially performing under names including Polka Tulk Blues Band and Earth before adopting Black Sabbath in 1969.

His eerie, distinctive vocals became central to the band's early sound. Albums such as Black Sabbath, Paranoid, Master of Reality, and Vol. 4 helped establish the dark, riff-driven style that became foundational to heavy metal. Osbourne also co-wrote many of the band's classic songs with Iommi, Butler, and Ward.

Osbourne left Black Sabbath after being fired in 1979. He was replaced by Ronnie James Dio, who sang on Heaven and Hell and Mob Rules. Other singers, including Ian Gillan and Tony Martin, also recorded with later versions of the band, but they were not the original vocalist. After leaving, Osbourne launched a successful solo career and later reunited with Black Sabbath on several occasions.