Vol. 4' was the fourth studio album by English rock band Black Sabbath, first released in September 1972. It was the first album by Black Sabbath not produced by Rodger Bain; guitarist Tony Iommi assumed production duties.

'Vol. 4' saw Black Sabbath beginning to experiment with the heavy sound they had become known for. Although most of the album's songs are in the band's trademark heavy style, others demonstrate a more sensitive approach which the band had never attempted before. The best example of this experimentation can be heard in the song "Changes."

The album cover features a monochrome photograph of Ozzy Osbourne with hands raised, taken during a Black Sabbath concert.

Key to the band's new sound on the album is Iommi's distinctive playing style that he developed after an accident at a sheet metal factory where he was working at the age of 17 in which the tips of the middle fingers of his fretting hand were severed. Iommi created a pair of false fingertips using plastic from a dish detergent bottle and detuned the strings on his guitar to make it easier for him to bend the strings, creating a massive, heavy sound.

'Black Sabbath' has been lauded as perhaps the first true heavy metal album. It has also been credited as the first record in the stoner rock and goth genres.