Ethan Cutkosky -- who plays Carl Gallagher on "Shameless" -- has officially been charged with DUI ... but it doesn't look like the kid was boozing.
The Burbank City Attorney filed charges against Cutkosky this week. He's facing one count of misdemeanor DUI -- which is only tied to drugs, not alcohol. He also faces charges for traffic violations related to his driving the night he was busted.
We broke the story ... Cutkosky was arrested earlier this month on suspicion of DUI. Cops told us they smelled weed on him, and that he even fessed up to smoking.
Sources say Cutkosky, who's only 18, is facing up to 6 months in jail, a $1,000 fine and the loss of his license if convicted.
If we know Carl ... he's already looking at his legal options.