Chris Kattan was high on drugs when he crashed his Mercedes into a truck on the 101 Freeway earlier this month ... according to the LA. City Attorney, who just nailed the comedian with a DUI charge.
A rep for the City Attorney's office tells TMZ, prosecutors filed one count of Driving under the Influence of Drugs, which carries a maximum penalty of 6 months in jail and a $1,000 fine for a first offense.
As we reported, Chris' car was seen weaving on the freeway early on Feb. 10 ... before careening into a coned area and slamming into a parked Dept. of Transportation truck, destroying his car in the process.
According to sources, Kattan -- who was not injured -- appeared out of it and told cops he had taken Rx pills before the crash. He was arrested on the scene.