Frenzal Rhomb is an Australian punk band that formed in 1991, based in the city of Sydney. The band's current lineup is Jason Whalley (vocals), Lindsay McDougall (guitar), Tom Crease (bass) and Gordy Foreman (drums). McDougall is also responsible for Rock Against Howard, a compilation by Australian musicians against John Howard's government.

They are named after Whalley's pet rat, who in turn was named after a light refracting box called the Fresnel Rhomb.