Sienna Unloads on Aussie DJ -- Piss Off!

Sienna Miller went absolutely ballistic on some Australian radio DJ this morning -- blasting the guy for bringing up one hell of a touchy subject ... Balthazar Getty.

"The Fabulous" Adam Richard of Australia's "Matt & Jo Show" found an ingenious way to bring up Getty during an interview with Miller and co-star Rachel Nichols for their new movie -- and even though it was all over the phone, you can still see the fire in Sienna's eyes.

To her credit, Miller didn't hang up -- she stuck through it and finished the interview.