What was Metallica's first album to feature producer Bob Rock?

Metallica was the first Metallica album to feature producer Bob Rock.

Rock began working with the band during the sessions for the 1991 self-titled record, commonly known as The Black Album. His arrival followed the production of earlier albums by Flemming Rasmussen and marked a new phase in Metallica's recording history.

Rock encouraged the musicians to record more collaboratively and pressed them to improve the songs' arrangements and performances. The sessions were difficult, but the resulting album became one of the most commercially successful heavy-metal records ever released. Its polished drums, layered guitars, and concise structures reflected the new production partnership.

Rock remained closely associated with Metallica afterward. He produced Load, Reload, and St. Anger, making the self-titled album the beginning rather than the end of a long collaboration. The answer is the official album title, not the informal nickname The Black Album.