Queens of the Stone Age Singer -- F**k Imagine Dragons ... F**K the Grammys

Queens of the Stone Age singer Josh Homme is still holding a grudge against the Grammys for cutting his performance short -- and for the band that beat him at the award show, he says ... "F*** Imagine Dragons."

In case you missed it -- the Grammys cut to credits in the middle of the Queens of the Stone Age performance with Nine Inch Nails.

NIN singer Trent Reznor already fired off "a heartfelt F*** YOU" to the Grammys on Twitter -- but Sunday in Houston, Homme spoke out about the diss for the first time.

He's also pretty pissed about Imagine Dragons winning the Best Rock Performance Grammy.