Michelle Obama -- KICKBOXER!!!!!

Dear Barack Obama ... DO NOT PISS OFF YOUR WIFE!!!

Check out this new footage of Michelle Obama going to town on a punching bag at the White House gym -- throwing punch combinations and a pretty devastating roundhouse kick!!

FLOTUS was showing off her Top 5 workout moves to celebrate the 5th anniversary of her Let's Move! campaign -- which is supposed to motivate Americans to get off their asses and get fit.

Michelle looks great in the video ... jumping rope, hitting squats and blasting her core.

#BringOnRondaRousey!