Ozzy Osborne was the lead singer of what heavy metal band?

Black Sabbath.

Ozzy Osbourne was the lead singer of the heavy metal band Black Sabbath. Formed in Birmingham, England in 1968, Black Sabbath is often credited with pioneering the heavy metal genre. With Osbourne as frontman, the band released several successful albums that have since become classics of the genre. These include their self-titled debut, “Black Sabbath” (1970), “Paranoid” (1970), and “Master of Reality” (1971). Osbourne left the band in 1979 to pursue a solo career but has rejoined Black Sabbath for various reunions since then. His distinctive voice and dramatic performance style, along with his wild off-stage antics, have made him one of rock music’s most enduring and iconic figures.