"Iron Man" is one of Black Sabbath's best-known songs. It was first released on their 1970 album Paranoid. It was later included on We Sold Our Souls for Rock 'n' Roll in 1975.

The song is known both for its story and for its popular riff. In the song, a man goes into the future to see what it is like. When he arrives, he sees the end of the world. On his way back to his his own time to warn people, his skin turns to steel, and so people don't listen to him or trust him. He is overcome with rage, and so himself brings about the very end of the world that he'd seen.

This song features one of the most popular riffs of all time. It is frequently used in television and movies, including Beavis and Butthead, School of Rock, and Futurama. It has been covered by Swedish death metal band Mental Break.