An off-duty EMT dressed in a Santa suit was charged with assault for throwing a beer mug at a bartender during SantaCon celebrations in the East Village, cops said Sunday.

Robalina Giannella, 30, was dressed as St. Nick when she got into a fight over her bill with the barmaid at the Village Pour House around 10:15 p.m. Saturday, police said.

The glass mug cut the bartender’s nose, a police source said. She was treated at the scene.

Giannella, an FDNY employee, was charged with second-degree assault.