Old Firm is a Czech metal band formed in 1991. They are known for their aggressive sound and politically charged lyrics. The band has released 12 studio albums, including their most recent, "IUS AD BELLUM" (2022). Old Firm has toured extensively throughout Europe and has shared the stage with bands such as Slayer, Megadeth, and Anthrax.

The band's name is a reference to the Old Firm, a rivalry between two Scottish football clubs, Celtic and Rangers. Old Firm's music is often inspired by social and political issues, and they have been outspoken critics of the Czech government. The band's lyrics have also been praised for their intelligence and wit.