This is the song that became the name of the band. They were using the name "Earth" when they realized another band had the same name. They liked the name of this song so they used it for their band. From Black Sabbath: The Ozzy Osbourne Years: "While rehearsing new material, the band formerly known as Earth experienced a supernatural experience. Geezer and Tony were playing new riffs for Ozzy and Bill when, much to everyone's surprise, they both strummed the same notes at the same tempo – although neither had ever before heard the other one play the piece! Convinced that this was an omen, Geezer christened the song and the group Black Sabbath (after the 1964 Borris Karloff's movie.)."

"Black Sabbath" was the first song on the first Black Sabbath album. The album cost $1200 to make and took about 8 hours to record.

As a result of the title, many fans associated the band with Satanism, an image they played up throughout their career. The song is actually about anti-satanism, or at least expresses a healthy fear of the devil. Godsmack lead singer Sully Erna describes this as "The darkest song ever." Godsmack got a big break when they were invited on the 1999 Ozzfest tour.

During a July, 2001 interview with Geezer Butler, Guitar World magazine explained that "having borrowed a 16th century tome of black magic from Osbourne one afternoon, Butler awoke that night to find a black shape staring balefully at him from the foot of his bed. After a few frightening moments, the figure slowly vanished into thin air." Geezer continued to describe how he "told Ozzy about it. It stuck in his mind, and when we started playing 'Black Sabbath', he just came out with those lyrics. . . It had to come out, and it eventually did in that song – and then there was only one possible name for the band, really!"

This has been covered by Vader, Widespread Panic, Dance or Die, Flower Travellin' Band, Amber Assylum, Jello Biafra (with Ice T), Acheron, Mistress, and Cryptal Darkness. Type O Negative covered this, except they changed the lyrics so that the song is from Satan's point of view. The song was called "Black Sabbath (from The Satanic Perspective)." It was on the albums Nativity in Black: Tribute To Black Sabbath and Type O Negative's The Least Worst of Type O Negative.